Some research hedges, cautious to describe animal emotions in the same words we use for human emotions, therefore using adjacent terms: “laughter-like” or “play vocalizations.” While it’s unclear if this is an attempt to assert human uniqueness, these researchers predicate laughter itself directly on understanding humor, which is a cognitive activity harder to measure than vocalizations.

Let’s return to the squirrels and my childhood cat. To me, the scene does seem to warrant humor or at least the acknowledgement that squirrels may appreciate irony. They could also have been delighting in their wit at evading feline capture. There is very little direct empirical research to help me name what my father and I witnessed. Studies show that squirrels have complex vocal systems, with a suite of barks, chatters, squeals, and kuk vocalizations, but researchers link these to alarm signaling, territory defense, and social communication. That doesn’t mean squirrels never make playful sounds, it simply means scientists haven’t yet clearly identified a squirrel equivalent to human laughter. What scientists research is usually linked to complex funding negotiations and protocol challenges. In relation to the latter, recall Panksepp’s discovery that the rats’ laugh was based on an observation that was inaudible to humans, after all.

Regardless, I think my multispecies memory matters. The world’s sacred texts sometimes describe animals not merely surviving in creation but delighting in it. Psalm 104 describes Leviathan—the great sea creature—as someone God formed “to sport with” in the ocean. The Hebrew verb lesaḥeq means not only “to sport,” but also “to play” or “to laugh.” A passage in the Babylonian Talmud (Avodah Zarah 3b) even suggests that God and Leviathan share a moment of play each day. In that sense, I like to think the God of my understanding gave squirrels a magnificent sense of play and humor too. &