I am so very sorry for your loss. I understand, it’s hard to believe something like this could happen but unfortunately, yes, squirrels will eat young birds. They also raid nests and eat eggs. Usually their targets are wild birds but think of it this way, they are rodents. Mice, rats and chipmunks will also destroy nests, eggs and baby birds if given the opportunity. So keep an eye out and predator proof your coop with them in mind as well. I know it’s hard to believe since squirrels (or chipmunks) don’t strike you as an animal that would do such a thing, they’re so cute and fluffy, but it’s in their nature. Squirrels also very regularly chew and eat shed deer antlers for calcium so take caution with your babies, a young bird or unguarded egg would provide the same nutrients for them.