There are 4 varieties of tree squirrels in California (omitting the tiny nocturnal flying squirrel, which is not considered a bug). Of the 4 types, two are native as well as 2 are presented from the eastern part of the United States. In their natural environments they eat a range of foods, consisting of a wide variety of seeds such as yearn acorns and also nuts, fungi, bugs, bird eggs, and young birds.