After completing our butterfly unit, we decided to do a Silkworm Unit. It has turned out into such a fun but long unit.Just to let you know this post is quite long and does contain quite a few photos!!
Around 100 silkworms and 96 eggs arrived near the end of September. We started feeding the silkworms with mulberry leaves and when our silkworm chow arrived we fed them that. We did have quite a few silkworms die, not sure if it was the weather (there were hot days and very cold days, not as constant as the silkworms need) or what it was.
These (right) were the eggs that arrived. The white eggs are infertile while the black eggs are fertile. We found out that it would take 7 to 20 days for these eggs to start hatching.
These are the silkworms that arrived. They just ate and ate and ate and grew so quickly.
We cleaned out their ‘house’ everyday and fed them three times a day. This is why we went onto the chow, as we were finding it hard to keep up with the leaves.
Here (right) is a picture of a silkworm eating.
If you were quiet and put your ear close to them, you could hear them. It sounded like soft rain!
This fascinated the boys.
They didn’t think that such tiny creatures could make such a noise.
Here is another picture of a silkworm eating.
At this stage the silkworms were getting quite big.
They were nearly ready to start building their cocoons.
As they were getting bigger, we tried to measure them. This was quite difficult as they would not stay still for very long.
We tried to keep them still by feeding them.
This silkworm is about 5 cm long.
Another picture of a silkworm being measured.
Most of the silkworms were around this size when they started their cocoons.
Some of them did reach 6-6.5cm and some were only around 4 cm.
Silkworms shed their skin 4 times during their lives.
Here is a picture of a silkworm shedding its skin.
We didn’t see much of this, but we did find a few shed skins in the bottom of their house.
When they were ready, the silkworms starting spinning their cocoons.
We had read on the internet that if you put toilet rolls in their house, they would build their cocoons in the toilet rolls.
We cut out toilet rolls in half to make them a little smaller and give us more ‘houses’ for the silkworms to build their cocoons in.
See the dirty patch at the front of the toilet roll in the photo on the right?
The silkworms empty themselves before building their cocoons.
What was really surprising to the boys was that the silkworms don’t eat again once they start their cocoons.
As moths they don’t eat, drink or fly!
This is our first cocoon.
The silkworm didn’t do as it was told and built it in a leaf instead of the toilet roll!
This was also our first one to hatch as a moth!
Some of our silkworms built their cocoons on top of each other.
Some of the toilet rolls have 2-4 cocoons in them!
This is a picture of a toilet roll that has 3 spinning their cocoons at the same time!
Here are some of our toilet rolls with cocoons in them. We ended up with quite a few!!
After being in their cocoons for a couple of weeks, the moths started to emerge.
When they first emerge, they sit on their cocoon and unwrinkled their wings and get the blood flowing.
Then they mate for up to 24 hours.
Then the female lays her eggs.
The White Moths only last a few days before they die.
They look really soft and furry.
But also a bit ugly at the same time.
The eggs are a lemon-yellow colour when they are first laid.
This is our first lot of eggs which we have seen laid.
I’m sure there are going to be plenty more!
Then our eggs started hatching.
Our first silkworm hatched and was only about 2cm long.
It looked like a little piece of black string.
Then all the eggs started hatching at once.
In a few days, we had over 30 baby silkworms!
They grew really, really quickly.
So now we were back to where we started!!
Silkworm Unit
A great link that goes into lots of details about the lifecycle of silkworms can be found here.
Learn all about the silk road here
A great site about the silk the silkworms spin: Here
Great activities and information about silkworms can be found here.
A great website with loads of information and activities about silkworms: click here.
A post about silkworms: here
For some silkworm facts look here.
A great page for kids all about silkworms: here
A fact sheet about silkworms: here
More about silkworms: here