2004). B-lymphocytes, the cells that produce antibodies, are initially produced in the embryonic liver, yolk sac and bone marrow, then move through the blood to the bursa of Fabricius (BF). Birds have a bursa of Fabricius (BF), which is an outpocketing of cloaca.
Most squirrels are vegetarians. There are a few exceptions like the flying squirrel. The flying squirrel will eat small birds, insects and definitely steal eggs from birds nest in order to make a meal. Generally speaking though, squirrels will mainly stick to things that are vegetarian related.
Tree squirrels are the members of the squirrel family (Sciuridae) most commonly referred to as squirrels. They include over a hundred primarily tree-dwelling species, native to all continents except Antarctica and Australia.hey do not form a single natural, or monophyletic, group, but instead are related to the various other animals in the squirrel family, including ground squirrels, flying squirrels, marmots, and chipmunks.