My bearded dragon i scratching at his tank

Question
I just got a 2 year old bearded dragon yesterday, he is about a foot long, he came with a 55 gallon tank it seems to fit him really well but every time i look over at him he is scratching at the tank and kind of looking at me. at first i thought he was hungry i put apples carrots and crickets in his tank and he ignored them. can you please tell me what his scratching behavior means?
Thank you :)

Answer
Hello Samantha,

Wow he is not very long for an adult.  
What type of lighting & setup are you using?  Do you have a bright white basking light, & a UVB light as well?  If you have a UVB light, what type & brand are you using, a florescent tube bulb or a compact/coil light?  
What type of thermometer are you using to measure the temps with, & what are the temps?
Scratching behavior can indicate that he either wants out, the temps are too hot, or he wants to brumate.  Are you sure you have a male, or could he be a female?
Are you offering greens as well?

Tracie