I'm guessing if any of my 4-Gray Tree Frogs were male I should be hearing noise from them by now??? For those who weren't here last year, I raised a bunch of batches of tadpoles, and ended up keeping 4 frogs. (from 3 different batches). So they are not quite a year old, and with my windows open the last few nights we all can hear the froggy chorus from outside -- but nothing from my tank does this mean I didn't get one male??