Momma rabbits nurse the babies, then hop back out. This is a “wild” rabbit instinct where the momma rabbits only visit the nest a few times a day, but staying close to draw predators away.
Putting the babies back in with the doe is probably the best thing you can do. Easy way to warm them up is to tuck the little ice cubes in your bra or tuck in your shirt tail and put them against your belly. When warm in one side, turn them over. Your natural body heat will warm them without overheating them.
No they can’t have cow milk. I’m pretty sure, now that you have them warmed up and returned to the nest, that the doe will take over and feed them. If this is her first litter, sometimes they just don’t know what to do and give birth on the wire.
I’m assuming that she pulled fur and made a nest. If not, pull fur from the roll under her neck and make a warm nest.
To check if she is feeding them, look at their tummies, they should be round and full.
Let us know how she and babies are doing.
