While we were doing the caterpillar-tickling experiment this week, the question of how to tickle the caterpillars had to be dealt with early on. I ruled out using our fingers on grounds of caterpillar mushiness, and that led to questions about why caterpillars are so very mushy anyway.
Direct experimentation was obviously out for this one, so we asked the iPhone: Why are caterpillar insides mushy?
According to the Caterpillar edition of How Stuff Works, caterpillars are built to eat. They’ve got a mouth to take in food and an intestine that runs through their entire body to digest the food and store it as fat. There’s also silk glands that make the silk the caterpillar uses to get around, to make a nest (or group home in the case of tent caterpillars), or to tie up snails for a tasty snack (in the case of some Hawaiian caterpillars, which unlike most of their brethren aren’t content to simply eat leaves). When it’s time to change into a butterfly or moth, caterpillars will also use their silk to attach their chrysalis (the protective shell that caterpillars live in while they are changing) to some safe place. And finally, there’s a nervous system that runs along the caterpillar’s stomach, which may or may not be helpful for those of us who wish to tickle them.
The point is, though, all these things are soft. There are no hard bits like bones or teeth like we have on the inside of our bodies, which is why caterpillars are mushy.
Note: Before your 4-year-old goes off to explore the mushiness of caterpillar interiors, it may be prudent to remind them that mushy creatures have defenses too. Some caterpillars are prickly and obviously unpleasant to squash, but even the fuzzy ones can cause skin irritation or an allergic reaction. Plus, it’s not nice to squash things.
- “Are caterpillars ticklish?” (Caterpickles)
- In which we perform a series of tests on caterpillars (Caterpickles)