What Animals Eat Acorns. It can cause various stomach problems in guinea pigs. Wildlife that consume acorns as an important part of their diets include birds, such as jays, pigeons, some ducks, and several species of woodpeckers.
Excessive consumption of acorns may be toxic to animals which find it difficult to digest tannins like horses or cattle. So instead of giving your guinea pigs acorns, you can feed them green fruits or fresh grass. Also, some mammals like fox squirrels, mice, voles, raccoons, opossums, flying squirrels, as well as a few other rodents eat these nuts, especially once they ripen and fall.
Low quantities of forage can also drive cattle to eat acorns.
Insects also feed on leaves, twigs, acorns, bark and wood of oak trees. The amount of toxins depends upon the species of oak tree. So instead of giving your guinea pigs acorns, you can feed them green fruits or fresh grass. Moreover, if you are much concerned about them then it is also important to tell you that generally, the squirrels eat seeds, different berries, acorns, and many other nuts.