While soft-shelled turtles do pass some urea through their kidneys like you and me, it’s very little, reaching about 6% of the total urine the animals produce. The rest of it leaves through their mouths. This novel method of taking a leak isn’t quite a unique take on the phrase “hitting the head.” Several varieties of fish are known to excrete urea through their mouths in a similar fashion, but this is the first time the behavior has been observed in a reptile.