Milk Frog Vivarium to dry??? HELP!!!!

[Katymcduk]

Hi, I am new to keeping any kind of pet that you keep in a vivarium. A few days ago I bought 2 baby milk frogs (Darrell and Greg) along with a basic start up vivarium (12x12x24) with a corner artificial plant, water bowl and trunk/cave and heat lamp.

I have two problems which may be related but worry me:

#1 They hardly move. It took them 24 hours to move a leg in the first day of getting them. Now that they have moved (When ever we aren't in the room) they stay to the top of the tank.
#2 I'm worried that the humidity of my vivarium isn't right. I thought that with the comber-nation of my misting everyday and the heat lamp would create a misty window kind of effect but it dry s out within minutes of me misting. Is this too dry? too hot? not hot enough - Is this why they are at the top of the tank?

I would be so grateful for any help I can get toward creating the perfect environment for my little friends