Ground squirrels are abundant in the developed areas of Mount Diablo. They are so abundant in some areas that they are creating erosion problems and damaging park roads and buildings. Ground squirrels are absent from many of the back country areas, possibly due to the extensive eradication program conducted by the county in the park up to 1974. Muskrats eat mainly cattails, and other plants, but will also eat clams and snails. These bats eat insects caught in the air.
Bats use echo-location to find their prey in the dark, which is similar to sonar.
Contrary to popular myth, bats are not blind, do not get caught in hair and our local bats are not likely to carry rabies. However, they do have sharp teeth, so do not handle any you find roosting. Bats are sometimes eaten by owls and snakes. Shrews are our smallest mammals. Despite their size, they are aggressive predators.