That one is easy. Frogs can swim and thus did not need to hitch a ride on the Ark along with two dogs, two, cats, two elephants, two border collies, two duck billed platypuses, two termites, two pterodactyls and a couple of cockroaches.
BTW-Do you want to meet up in Mongolia to hunt pterodactyls?
Sure, however this weekend is out, because I'm taking my grandkids to the seashore to go dig up some trilobites. Ever had yourself trilobite chowder?