frog won't eat

[beyowulf]

I just bought a white's tree frog and I'm not sure if he's eating, I haven't seen him eat, and there are crickets in his tank that I put in there a few days ago. ( I didn't put many in, only about 7 small ones.)

I'm wondering whether I'm doing the whole setup wrong or something, so help me out if you can

I have moss in the bottom of the tank (the tank is about 15 gallons, its one of those vertical ones, with a wire-mesh lid). I forget the name of the moss, but it's a medium brown and comes in a bag. I have a really shallow bowl of water in the bottom too. There's a stick with some plastic vine twisted around it as decoration that runs the height of the tank.
my house is really cold, so i have a heat lamp and an undertank heater.

I've been spraying him and the tank with unchlorinated water once or twice per day too.....

hope you can help me

~Jen