Living+Organisms

=Live Animals=

K - Ladybugs - Enhance Unit 10, 11, 12 1st - Silkworms - Enhance Unit 9, 10 - Start with eggs ~ 30 per teacher 2nd - Butterflies - Enhance Unit 10 - After Spring Break ~ 10 per class 3rd - Tadpoles - Enhance Unit 6, 7 - available around March 23 ~ 6 per class or set up school aquarium 4th - All animals need to be accessible to this grade. Students could also work with silk worms if available. 5th - Students may observe other organisms but no animals will be purchased specifically for this grade.

**Tadpoles** - Music video []

**Silkworms**

= Don't forget that silkworms will eat the leaves of a mulberry tree. Be sure the tree hasn't been sprayed with any pesticides before using. If you or anyone at your school has access to one and it is leafing out it sure beats cooking the food. You can save the powder for use at a time you can't get leaves. The newly hatched worms can eat the tender new leaves that are 1/2-1 inch long. As the worms get larger and their jaws get stronger you can use larger more mature leaves. This is just a suggestion. ~ Adele =

This document is a resource for K-12 educators. It contains curriculum ideas, silkworm-raising instructions, and the history of silk. Imbedded __ hyperlinks __ allow the user to skip around in the document. The most current version is available on the Internet at [].  Silkworms are easy, fun and educational to grow in a classroom or at home. Most children think they are cute, and nobody is allergic to silkworms. They are easy to care for and can help make your students excited about science. After hatching from an egg, the silkworms eat mulberry leaves and grow larger. When they are finger-sized, they each spin a cocoon, pupate inside the cocoon, then emerge as a moth to mate and lay eggs. The eggs hatch into silkworms in a few weeks, and then the cycle continues. Silkworms go through four stages of development, as do most other insects: egg, larva, pupa and adult. The larva is the silkworm caterpillar. The adult stage is the silkworm moth.  Silkworms were originally domesticated in China thousands of years ago. Stories have been handed down through the generations and are based party on fact and partly on legend and myth. The tale which persists is that about 2,640 B.C. a Chinese empress, Si-Ling-Chi, was watching the glistening amber cocoons that little worms were spinning in the mulberry trees in the palace gardens. She unwound one of the threads on a cocoon and found that it was one, very long strand of shiny material. Fascinated, she pulled strands from several cocoons through her ring to form a thicker thread. Eventually, with the help of her ladies of the court, she spun the threads into a beautiful piece of cloth to make a robe for the emperor, Huang-Ti. This magnificent material, silk, became known at the "cloth of kings". For thousand of years the royal family of China had silk. The Chinese kept the secret of how silk was made for 2500 years. Silk cloth was sold to the West, but the source of the shiny thread that made the material was not revealed. The penalty in China for telling that the silk came from the cocoons of the little silkworms was death! Some very strange ideas were formulated by Westerners to explain the origin of silk. Here are a few: Silk came from the colored petals of flowers in the Chinese desert, silk was made of wondrously soft soil, silk came from a spider-like animal that ate until it burst open and the silk threads were found inside its body, and silk came from the silky fuzz on special leaves. These ideas seem far-fetched today -- but in ancient times they were serious theories. Legend has it that the Japanese carries off four Chinese maidens, who knew the secret of silk, along with mulberry shoots and silk moth eggs. Today Japan is the leading producer of silk! Another story is that a Chinese princess married an Indian prince. She carried silkworm eggs and mulberry shoots to India in her elaborate headdress and the secret of raising silkworms in her head. Two Christian monks told Emperor Justinian of Constantinople that they had learned the secret of silk. Justinian send them back to China to get eggs and mulberry shoots for him. They returned many years later with the eggs and shoots hidden inside their hollowed-out walking sticks. Since Justinian was the emperor of Constantinople, a crossroads city, the secret soon spread throughout Europe. There are many more interesting stories about the history of silk. Have older children do some research in the library and report to the class. Today silk can be worn by anyone -- not just emperors and noblemen and their families. Silk is made into many lovely fabrics, such as satin, velvet, chiffon, crepe, brocade, taffeta, faille, and shantung. A good class project would be to see how many different kinds of silk cloth could be collected and put them on a chart for the kids to see and feel. The beautiful colors of silk would also make an excellent chart. Modern silkworm moths have been bred to make white silk instead of the amber-colored silk of their wild ancestors. They also have large, fat bodies and tiny wings, so they cannot fly. This makes it easier for silkworm farmers to raise them (and easier for teachers, too!). If you were to release a domesticated silkworm moth into the wild, it would not be able to survive or reproduce.  If the silk moths are allowed to emerge from the cocoons, they would make holes in the silk thread. Silkworm farmers kill the pupas inside the cocoons by baking them in a hot oven. Then they soak the cocoons in boiling water to loosen the threads. A person finds the end of the thread and places it on a winding bobbin. Then a machine unrolls the cocoon, winding the silk from five cocoons together to make one silk thread. Then the thread is woven into cloth. Zhejiang province of China is the main source of Chinese silk, and contains more than three hundred silk mills. ** and FAQs ** The Latin (scientific) name for the silkworm is bombyx mori. Silkworms are insects. All insects have six legs in the adult stage. Silkworm caterpillars have six real legs, plus five pairs of pseudopods (false legs) on the rear of the body. The very rear of the body, which is split, is used for grasping twigs and leaves. Insects have no backbone or skeleton, but instead have an exoskeleton (exterior shell). Some insects like cockroaches have a hard, crunchy shell. Silkworms and silkworm moths have a soft skin. Silkworms shed their skins four times while growing. These growing stages are called instars. Silkworms are cold-blooded, as are all insects. A warm-blooded animal always has the interior of its body at the same temperature (98.6°F or 37°C for a human) unless it is sick. If their interior temperature gets too high or too low, it will die. A cold-blooded animal's interior temperature is usually within a few degrees of the air around it. The only warm-blooded animals are mammals and birds. All animals without backbones are cold-blooded, which includes silkworms and all other insects. However, while moving around, all animals' muscles generate heat. If you have a covered container with lots of big silkworms, when you take the lid off, you can feel the heat that was trapped in the container. Male moths are smaller, and have a flap of skin at the rear. Females periodically extrude a yellow T-shaped scent gland out their rear end. Look at the pictures in Sylvia Johnson's book for close-up photos to help you distinguish male from female. The smallest caterpillars, which make the smallest cocoons, turn into male moths. The big caterpillars turn into female moths. The medium-sized worms ones can go either way. Wild silkworms all make yellow silk, to be camouflaged with dead yellow leaves. Over the centuries, silkworm farmers selectively bred for whiter and whiter silk until they achieved the pure white we see today. Silk farmers prefer pure white because it can be dyed any color without having to bleach it first. Some people have blue eyes and others have brown eyes. When a blue-eyed woman marries a brown-eyed man, some of their children will have brown eyes and others will be blue-eyed. Silk color works in a similar manner. Almost all commercial silkworms make white silk. There are a few silkworm varieties that make yellow, orange and pale-green silk. When you cross-breed a "white-silk" silkworm moth with a "yellow-silk" silkworm moth, some offspring will make yellow silk and some will make white silk. The color of silk is determined by the silkworm’s genes. They don't eat (or drink) anything. They mate, the female lays eggs, and then they die within 3-6 days. Many other types of insects (like mayflies) follow this pattern. All adult butterflies and moths have mouth parts and digestive tracts adapted for sipping liquids. Silkworm moths still have a mouth and rudimentary gut, since they're descended from an ancestor that fed in adulthood. Silkworms operate entirely on instinct. They have a group of nerve cells that controls their bodies, but it is too rudimentary to be called a brain. ** links ** A teacher in Pennsylvania, USA has information at [] An excellent five-minute slide show about silk and silkworms is available (from Cincinnati, Ohio, USA) at [|http://BugLady.clc.uc.edu/showit/silk.htm]. Note that the file takes about 15 minutes to download on a 56K modem, so be patient. It's worth it! You will need a special viewer to see the slideshow. The website has a place to click to download the viewer. When you download the viewer setup program, save it in C:\Downloads. Then open up C:\Downloads to install it. The computer will ask where you want to install it. For Netscape, install into C:\ProgramFiles\Netscape\Communicator\Programs. For IE under Win95, install into C:\ProgramFiles\Plus!\Internet Explorer, For IE under Win98, install into C:\ProgramFiles\Internet Explorer. For help with installation, email the author. General information on butterflies can be found at [] or [] If you would like to download gorgeous silkworm pictures in incredible detail (but it will take a VERY long time - each file is around half a megabyte), check out [] A site with general butterfly information (but it loads VERY slowly) is [] Silkworm information in Spanish can be found at [] Please email the author if you find other worthwhile sites!  There are many ways to integrate silkworms into your curriculum. Some teacher-tested ideas appear below. If you have ideas to share or have questions about silkworms, please email the author kayton@alum.mit.edu. The book __Silkworms__, by Sylvia Johnson, is excellent for children and adults alike. It has amazing photos. Most bookstores can order it, or you can order it from [|http://www.amazon.com]. The paperback is ISBN 0-3225-9557-5 (about US$6). The library binding edition is ISBN 0-8225-1478-8 (about US$16).  Try these teacher-tested ideas or invent your own!
 * Are silkworms warm-blooded or cold-blooded?**
 * How can you tell if a silkworm is male or female?**
 * Why are some cocoons yellow while others are white?**
 * What do silkworm moths eat?**
 * Do silkworms have brains?**
 * Silkworm math**. Have the children measure the length of the silkworms and graph them as they grow.
 * Rainfall**: When the silkworms are large, take the lid off the container and have the children be extremely quiet. They will be able to hear the sound of the silkworms moving around! It sounds like a gentle rainfall. The sound is not chewing, but their little suction-cup feet lifting off the leaves and plopping back down again.
 * Silkworm pet**. Give each child a silkworm in a small cardboard cup or carton. Have them put in a fresh leaf twice a day, and empty the droppings and dried leaves. Put in a stick and they can see the silkworm crawl around. Wait until the caterpillars are two weeks old since there is a high mortality rate for the first few weeks.
 * Heartbeat**. With a full-grown caterpillar, you can easily see the heart pumping blood through the translucent skin. The heart is located at the rear end of the caterpillar on the top. You can see it pulse. The main artery carrying the blood is where the backbone would be if it had one.

Silkworm Chow - powder food recipe Use at least 1 ½ quart microwave safe container for each ½ pound of chow to prevent a boil-over.

1) Add ½ pound of chow to 3 cups of hot tap water and mix thoroughly. 2) Cover with plastic wrap. 3) Cook on high until mixture boils. 4) Remove, stir and repeat step 3 for approx. 1 minute and stir again. 5) Press a sheet of plastic wrap into the hot food to prevent condensation. 6) Cool, cover and store in refrigerator. 7) Wash hands before handling food to prevent contamination.

COOKING INSTRUCTIONS (For 1/2 lb Powdered Silkworm & Hornworm Chow) MICROWAVE OVEN (preferred method) CAUTION: Use at least a 1 1/2 quart microwave safe container at least 5 inches deep for each 1/2 lb. packet of Chow or it may boil-over. 1). Add 1/2 lb. of powdered Chow to 24 ounces (3 cups) of hot tap water and mix thoroughly by hand until all traces of powder are gone. (A wide butter knife works well for mixing.) 2). Place a sheet of plastic cling wrap over the top of the container to retain moisture. 3). Cook on high for several minutes until mixture begins to boil (it will puff up and rise to about one-third higher than its original level). 4). Turn off microwave and stir for a few seconds for uniform consistency. 5). Repeat step number 3 (for about 2 minutes), and then step 4 again. 6). Immediately place a sheet of plastic wrap inside the container and press it against the chows surface so it clings directly to the surface of the hot chow. This will prevent excessive condensation from forming and help keep the chow sterile. 7). Allow to cool and then put lid on and place into refrigerator. 8). Remove from fridge, peel back plastic wrap, slice and serve when firm. After the Chow cools, it should have a consistency similar to soft cheese. WARNING: Do not handle the cooked Chow unless your hands have been thoroughly washed. Silkworms are very sensitive and susceptible to bacterial problems if their food is not kept sterile. Hornworms are less sensitive. NOTE: The cooked Chow will keep for a month or more in the refrigerator if kept airtight. The powder can be stored for about 6 months if kept in a cool dark place, or longer in a refrigerator (WE RECOMMEND REFRIGERATING) Each 1/2 lb. of powder makes approx. 2 lbs. of cooked Chow, enough to feed/grow approx. 350 silkworm eggs into 1 1/2 to 2 inch long worms.

COOKING CHOW ON STOVE-TOP NOTE: A double boiler will give better results than cooking directly on the stove top burner (it reduces stirring and prevents burning). We recommend using a microwave oven (see above). 1) Pour 1/2 lb. powdered Chow into a pot containing 3 cups of hot tap water. 2) Mix well by hand (it starts out thick but thins out as it gets hotter). 3) Place on stove top and bring to a boil for 5 minutes (stir continuously if you are not using a double boiler to avoid burning). 4) Stir mixture vigorously (for uniform consistency) for a few seconds immediately before pouring (for faster cooling - pour into a container to a depth of about 3 inches). 5) Immediately place a sheet of plastic wrap over the surface of the mixture and press so it clings directly to the surface of the hot chow. This will reduce condensation and will help keep the chow sterile. 6) Allow to cool and then put a lid on and place into refrigerator. 7) Peel back plastic wrap -- slice and feed when firm. WARNING: Do not handle the cooked Chow unless your hands have been thoroughly washed. Silkworms are very sensitive and susceptible to bacterial problems if their food is not kept sterile. Hornworms are less sensitive. NOTE: The cooked Chow will keep for a month or two in the refrigerator if kept airtight. The powder can be stored for about 6 months if kept in a cool dark place, or up to a year in a refrigerator (WE RECOMMEND REFRIGERATING) Each 1/2 lb. of powdered silkworm chow makes approx. 2 lbs. of cooked Chow, enough to feed/grow approx. 350 to 500 silkworm eggs into 1 1/2 to 2 inch long worms. Each pound of powdered chow makes 4 pounds of chow when prepared, only takes about 5 minutes in a microwave oven.