baby beardie being bad

Question
I was recently given a baby bearded dragon and it has an attitude. Every time I try to pick it up it immediately tries to bite me, and/or hiss, and/or run away. Is there anything that I can do to correct this behavior.  
FACTS
The beadie is 3.5" nose to vent (9"nose-tail tip)
In a 55g terrarium,well ventilated, 10.0 UVB bulb, underground heating pad, basking area, hiding places, places to climb, reptile carpet for a substrate. I (try) bath it at least once a week, and mist it with water every other day (really likes it i think).
I feed it collared greens, melon, squash, and berries among others twice a day, feed it calcium dusted crickets once a day (15-20, 2-3 weeks old), mealworms and the occasional waxworms. Change its water minimum 2 times a day and has a shallow dish of water about its size that it  likes to sit and poop in.
NOTE: The person that I got it from had it in a 5 gallon tank and only fed it "greens" and bearded dragon pellets, no insects and it was not handled much before me. Also I do not remember seeing any source of heat. I have had it for a little over a month, and the vet says it is healthy, except for being a little thin, a problem that I have since corrected and my vet agrees.
Can you help? Am I doing something wrong?  

Answer
Hello Kelsey,

Oh boy, that is not good.  The baby must have been mishandled previously or he doesn't feel good.
Let's review your setup a little bit.
The tank size is perfectly fine, no problems with that at all.  The 10 UVB, is it a fluorescent tube bulb, or a compact coil light?  What brand is it?  How close is it to your dragon?  Are you using a bright white basking light directly beside it as well?
What are the temperatures in the tank, & what type of thermometer are you using?  A stick on type, a digital probe or a temp gun?
Great that you are using carpet, & no sand.  So, he should not be impacted unless he was housed on sand previously.
The feeding schedule & variety is very good, so continue with that regime.  The calcium dustings should be 5 times per week, once a day, just as you are doing so now.
I would not use an undertank heater during the day.  Instead use just an overhead basking light such as a regular house hold light bulb or a halogen flood bulb.  At night, if it gets cold, then you can use the undertank heater.  They need heat & light from above, during the day to maintain activity levels.    

Do you have any pictures of him?

Tracie