“Perhaps to a layperson,” his companion said. “I’m not convinced that ‘tool use’ is as simple as all that. The rock is something in their environment that they make use of… but then, so are the shellfish. We may as well label eating as ‘tool use’ since it involves making use of an object. If otters could be observed shaping the rocks, fashioning something from them…”

“So, then, when a bird strips the bark off a twig before using it to dig insects out of…”

“Well, now you’re just being ridiculous.”

“How am I being ridiculous?” the first man asked. “It fits the definition you just gave.”

“Birds and twigs… instinctive behavior!”

“Who says tool use can’t be instinctive?”

“If we’re talking about tool use as a meaningful signifier of intelligence…”

“That’s such a slippery term.”

The floating otters watched the boat drifting slowly out of sight, listening to the babel of increasingly agitated sound coming from the cute, clownish creatures who stood on the floating hulk. They almost sounded intelligent.