Do any types of caterpillars eat wood?

Yes, some do eat wood some are herbivores only eating plants and natural things and some are omnivores eating alive items. But it is best if you do not feed it wood because if it digests it inproperly it could lead into serious problems with the caterpillar such as:

1: not eating food and leading to starvation.

2: increase in pooping structure.

and last but not least 3: may die from anything other in the wood.

thank-you and i hope i helped in your question!

~rosy