They'd be eating them if they were outside, right? So my opinion would be yep! Just make sure you're giving them grit!
I've seen a few inchworms here, but my abundance is tent caterpillars. My boys and I spent about an hour picking them off the trees and ended up with about a quart of them! My youngest refused to let me feed his to the chicks...he wants to keep them as pets (gah! a hundred caterpillars are now in a critter cage!). The ones I caught...well, my 6 chicks ate like kings and queens last night
! They ate so many they couldn't finish them all...I picked the leftovers out and dumped them in my son's cage lol.
Since your chicks are younger than mine, I'd say not to feed them too many...since the nutrition they need they get from the chick starter. I'd give them as treats once a day. That's what I did with bugs I found when my chicks were your chicks' age.