A squirrel does make noises, mainly in the form of a bark. When threatened or injured, squirrels make a crying sound.
A squirrel's bark is much different than that of a dog. Their barks are higher pitched and they use it to communicate with one another. They also use it when chased by another squirrel. A squirrel's cry often resembles a chirping sound, and it is commonly followed by a few barks. The grey squirrel is one species that makes additional sounds called whining. This whining attracts other squirrels in the area. Squirrels also make scratching sounds, as any homeowner who ever dealt with a squirrel in the attic or on top the house can attest.