The leaves were all mature. Maybe they don't like them because they are wine grape vines. I've gotten them to eat sliced apples and carrots so they'll probably be ok.
I was planning on breeding them all and having 1000s of worms eating my grape leaves, but I guess that won't work.
I...
The leaves were freshly picked. I've only seen them take quick nibbles then wander off. So far 6/50 of the worms have been eaten by others. I ordered some powdered food. It'll take 4 days to get here. So probably none of worms will survive until then -_- total waste of money.
I decided to try breeding hornworms since I heard they eat grape leaves. I have loads of grapevines in my backyard so I thought it would be easy. I have now run out of the food that they came with and have added grape leaves to their container. They seem to be ignoring the leaves completely...