(You can speed up the process by keeping your classroom warm all the time.) Eggs will arrive a dark purple color, and a day or two before they hatch the eggs will turn a light blue/gray color. The worms will be black once they hatch.Usually wait 24 hours after the first one hatches to offer food, or contact with the food(depending on what type you have) could kill the unhatched worms.Still have questions? In Australia, a Silkworm will naturally hatch in late July to early August – depending on the weather where you live – this time amazingly coincides with the Mulberry Tree regaining its leaves after the tree loses them in Winter. Feeding beetroot leaves may make them spin a pinkish silk, which can be cool! Fertile eggs might hatch in about two weeks after being laid in the middle of the summer, but they usually won't hatch unless subjected to "winter" in your refrigerator for at least several weeks. )   However, even if your students are unable to see the complete cycle, it’s still a worthwhile activity as they watch the eggs hatch and the larvae grow.  And at the end you’ll have the eggs you need for next year, and can start the process any time, as long as you have food available (mulberry trees don’t begin to leaf out until mid March, or later, depending on where you live).After 2-3 weeks the moths emerge from their cocoons.  They will mate as soon as a mate is available.  The eggs will show up within a day or two.  At first they will be lightly yellow, but as the larvae began to grow they will turn black.  This usually takes a few days.  If you don’t put the eggs into the refrigerator, they will begin to hatch within a couple of weeks.  Placing them in the refrigerator simulates winter in their native environment (China and Japan).  The moths don’t eat or drink, and they die after laying the eggs.  You can keep the cocoons to display next year, and for your students to “dissect.”  If you boil them in water, the silk will unwind, however it won’t be in one long piece because of the hole in the cocoon.There are lots of things to do while the eggs are hatching and the larvae are growing:Hatching silkworms is a very up-close and personal activity for students, and is just as appropriate for 3 year olds as for 6th graders!Enter your email address to follow this blog and receive notifications of new posts by email.I am in the process of transferring this blog from its previous website. They require at least room temp. We send full hatching/incubation instructions with every order and a guide for raising silkworms through their life cycle. Blog at WordPress.com. They should be a dark purple color now, and in ten or so days, before they hatch, they'll turn light blue or grey. In much of the country that doesn’t give enough time to complete the cycle by the end of the school year. Once you take eggs out of the fridge, they will hatch in 7-20 days, or maybe not at all. )The first time you hatch these eggs, you’ll have to buy them, unless you have a friend who has some and will give them to you.  But from then on you can collect the eggs that are laid, keep them in your refrigerator, and take them out the next spring whenever you’re ready to start again.  You can get them from It takes 3 to 4 months for the cycle to complete.  In nature, silkworm eggs hatch when mulberry trees begin to bud.  In much of the country that doesn’t give enough time to complete the cycle by the end of the school year.  You’ll need to start the process in mid February or early March to complete the cycle by early June.  (You can speed up the process by keeping your classroom warm all the time.

This will chill them in a sort of hibernation until you are ready for them to hatch. However, it is recommended that you feed them mulberry leaves as it is safer and better for the silkworm.