Betta and Dwarf Frogs?

I just got two african dwarf frogs today. They have a nice big tank, and I also put in a betta fish with them. However, the ADFs stay at the bottom of the tank. And come up for air occasionally and the Betta stays at the top and came down onc or twice. Also, when the ADF's get air, they go up quickly, and swim back down like a dart. (they did that before I put the betta in, though) The ADFs had tank mates in the pet store, however the Betta has never been housed with anything else. This is all of their first day in this tank. Are they scared of eeach other? Any feedback would be appriciated.