“Bask” is the most widely used collective noun for crocodiles, and it names the behavior directly: crocodiles hauled out on a riverbank or sandbar, jaws often open, soaking up the sun. As cold-blooded reptiles, crocodiles can’t generate their own body heat, so basking is essential, not optional. It’s how they warm up enough to hunt, digest food, and move efficiently.
The open-mouth posture common during basking, sometimes called “gaping,” helps crocodiles avoid overheating even while absorbing warmth, working almost like a built-in cooling vent for the brain. Basking spots tend to be prime real estate, flat, sunny, close to water for a quick retreat, and crocodiles will often share the same stretch of bank without much fuss, since the activity itself doesn’t require cooperation, just proximity.
A bask can range from just a couple of crocodiles to a dozen or more, especially in productive habitats where good basking real estate and abundant food overlap.
Example: “A bask of crocodiles stretched along the sandbar as the morning sun climbed higher.”
Related: Collective Nouns for Reptiles · What Is a Group of Crocodiles Called?