The fleas feed on wild rodents, such as the rock squirrel in the Southwest and the California ground squirrel in the Pacific states.
From the healthland.time.com
A red squirrel jumping from rock to rock in Kielder Forest, Northumberland.
From the guardian.co.uk
But how does a phone tell the difference between a squirrel and a rock or a tumbleweed?
From the newscientist.com
Turns out the rock rat is unlike any rodent known to science, a fetching cross between a large dark rat and a squirrel with some kinship to the guinea pig and chinchilla.