This is a excerpt from the up coming fire-bellied toad care article -
"You may not be able to identify a female out of breeding season, but there are two sure fired ways of finding male toads. One is the call, which sounds like a soft moan, and the other is the behavior of the male. Most males will be engaging their housemates in amplexus rather regularly. They never seem to stop. Without proper conditioning of both genders, which involves a cooling period, nothing will become of this."