Full Idea
If an animal has a desiring part, it is capable of moving itself. A desiring part, however, cannot exist without an imagination, and all imagination is either rationally calculative or perceptual. Hence in the latter the other animals also have a share.
Gist of Idea
Self-moving animals must have desires, and that entails having imagination
Source
Aristotle (De Anima [c.329 BCE], 433b27)
A Reaction
Maybe if you asked people whether other animals are imaginative they would say no, but this argument is strong support for the positive view.
Book Reference
Aristotle: 'De Anima (on the psuche)', ed/tr. Reeve, C.D.C. [Hackett 2017], p.62