It is a natural thing, as they are experimenting with what they instinctively know will happen soon. They really are not getting air but rather "checking things out on the surface".
Call them nosy, but they somehow know that they will be out in the open real soon. Do your tads have any legs yet? If so then you will see a lot more of this inquisitive behavior as they get closer to being frogs.
They are interesting creatures to watch aren't they?
Deb
