Image: Jean-Jacques Boujot/Flickr
It's one of those stories you hear sometimes and fervently hope is an urban myth: rats climbing up through your plumbing and into your toilet. But a new video from National Geographic shows how a rat's physiological and behavioral adaptations make this feat all too easy.The video accompanies a blog post from National Geographic online science editor Erika Engelhaupt, chronicling her months-long battle with a nest of rats that made themselves at home in her plumbing.The path to infestation starts in the sewers, which are rodent havens. Rats' sharp claws enable them to scale smooth, vertical surfaces, like the pipes going up and into your home. But how do they get through the bendy, water-filled toilet pipes?Rats are surprisingly excellent swimmers. They can hold their breath for up to three minutes, and can tread water for three days. And once they reach the top of the toilet's U-bend, there's a tiny pocket of air that enables them to swim on, up and into your toilet bowl.Rats are also capable of collapsing their ribcage, due to the hinge-like connection between their ribs and their spine. This enables them to squeeze through passages the size of a quarter, so your toilet tubes pose no problem.But even though rats can make the journey with ease, it rarely seems worth it for them, and rats in the toilet is not a super common problem. The Washington, D.C. Center for Rodent Control only gets a few callers with this problem in a year. I can live with those odds.