An octopus can fit through any hole larger than its beak.

The story behind the answer

True. An octopus has no bones and is almost entirely soft, so the only rigid part of its body is its hard, chitinous beak. That means it can compress and ooze through any opening wider than its beak, making narrow crevices, pipes, and small gaps potential escape routes.

This flexibility helps octopuses hunt in tight spaces and evade predators, and it’s one reason aquariums use secure, beak-proof enclosures. Memory tip: “Beak = bottleneck.” If the hole is larger than the beak, the rest of the octopus can follow.