Yeah, there's an equivocation in this reference. The "animal" in "animal spirits" doesn't refer to non-human lifeforms, rather it means "of or relating to a soul". The expression itself is an obsolete medical term which designated what people from late antiquity to the modern period thought was the cause of bodily movement.

By the early 20th century, it had become a somewhat quaint and tongue-in-cheek expression. To say that someone was "full of animal spirits" was to say that a person was lively, restless, or something like that.

There's without doubt a conflict between rationality and irrationality in Keynes' usage of it. But that conflict isn't alluded to through a reference to "animals", in the contemporary sense.

https://en.wikipedia.org/wiki/Animal_spirits_(Keynes)

https://neurophilosophy.wordpress.com/2006/11/16/exorcising-...