Can you spot two Monarch caterpillars in this photo?
They were tiny when they arrived last week. Since then, they’ve been munching on Common and Swamp Milkweed and growing fast.
As they grow, their bodies will become too large for their skin. When it’s too tight, they’ll shed their skin, wriggling out of it to expose soft new skin underneath. 
The bigger skin will harden to protect the Monarch as it continues eating and growing. Monarch caterpillars shed (or molt) five times! Sometimes, they eat their shed skin.
The caterpillar in this photo just molted. See the black circle above its head? That’s its shed head capsule. It pops off like a helmet when the caterpillar begins to molt. It already looks small next to the caterpillar.
Monarchs spend 10-14 days as caterpillars before transforming into a chrysalis.
Next time you’re in the library, please stop by the Youth Services Desk to say “hi” to the caterpillars!
