New FBT - help introducing

[jlong]

I'm pretty new to FBTs. I got my first about four months ago. Hoppy (named by my four year old) has a ten gallon aquarium with part water and part land. When we bought Hoppy, the clerk told us she was a girl because she didn't have much webbing between her toes. We decided to get Hoppy a friend, but when we introduced them today, Hoppy very aggressively jumped on top of Hopper (my two year old named this one). Hopper was not happy with Hoppy, so for now they are separated by a screen. I got to looking at Hoppy, and she (now thinking he) has much more webbing between the toes than when we bought her (him). Hoppy also sort of chirps/croaks. Do females do vocalize at all or is that a male thing? Hopper (the new one) is smaller, and I don't want her to get hurt by Hoppy. Hopper has very little webbing between her toes, but now I'm wondering if all young frogs have little webbing and that comes in as they grow. I hope we didn't end up with two males as I've read they can be pretty aggressive. Right now, Hoppy is just sitting right next to the divider and chirping away. Anyway, I'd prefer not to have a permanently divided tank. Any ideas on making this a more successful introduction? Thank you!

[Bombina Bob]

Welcome to the forum! FBT males only vocalize if they are calling for a mate or if another male accidentally mounts him making a chirping sound (Get off me!) saying Im not a female. However im not sure how to stop the makes from calling.

[LordofStuff12]

Everything you describes sounds like ordinary fire belly behavior. My only concern is that if your recent addition, Hopper is much smaller, (he/she) could be injured. As long as both frogs appear healthy and are in the same ballpark size, you should be fine. Aggressive mating behavior is normal, especially in the spring. Just make sure there is a land area of the tank, that way she can get a break from time to time.