Even if you don’t know what a “blep” is, you’ve probably seen it. That’s when a cat, particularly one that normally carries himself like royalty, lets his mouth go slack and his tongue hang out. The cat, not paying a bit of attention, can stay like that for quite some time, giving cat photographers an opportunity to preserve them at their silliest. Dogs do it, too, but we don’t consider it odd when dogs blep. What causes a cat to do that? It turns out there are quite a few reasons, and possibly more we don’t understand yet. Mental Floss goes over those reasons from veterinarians and cat experts for why your cat bleps, and none of them involve communicating rudeness.