Video taken in Revillagigedo, Mexico, in the waters off the country's Pacific coast, just might prove otherwise. During a dive organized by Quebec-based company Scubacadémie, divers captured footage of whitetip reef sharks huddled together on the ocean floor near an underwater cave. Some appear to fidget about while others lie completely motionless. The large pile of sharks appears to be roughly 20 strong and unbothered by nearby human presence.

While the scene may appear odd to the untrained marine enthusiast, the arrangement is quite common.

National Geographic Explorer-in-Residence Enric Sala has spent quite a bit of time in marine ecosystems around the world. In an emailed statement, he noted that sharks can often be seen piled up like this, not