My 5 week old Buff Orpington's don't like earth worms. Is this normal, I always assumed chickens love earthworms. Though they literally eat everything else under the Sun. I'll turn logs and lumber over for them and they eat the slugs, snails, ants, spiders, larva, etc, but won't touch the earthworms, even the small ones. One even tried to eat a salamander today.
You just never know. There are ones here that grow dandalions just for their birds, but mine won't touch them and they are adults. Just like you and others and foods, some like it and some don't. I would worry about it to much.