I noticed that as well, a huge activity difference between the slow moving crickets from petsmart and the more healthy active ones I got from Carolina Crickets, with me I put a few less in there it took mine a while to time his lunges better but now.. he roars out of his little hole when I drop those faster ones out grabbing them as fast as they move in front of him and I add one or two more at a time when he gets those done, when he slows down I let him alone, the 1-2 left in there are usually gone by the morning now. I have a few dubia that I am feeding up and will try n get him to eat this weekend, have to take him out of his enclosure for those though so will see how it goes.