Is my gecko sick?

[PartywithPayton]

My name is Payton, I just got a crested gecko about a week ago. His name is Charizard, and he is probably around eight or nine weeks old? Possibly a little older, but he is still pretty small. When I first got him, around a week and a half ago, I only started feeding him crested gecko diet because I decided I wanted to give him about a week to get used to the new environment before giving him crickets. He seemed to do pretty good, he moved around a lot at night, and found himself a nice spot he liked to hide during the day. I didn't touch him at all the first week, I thought it would be better not to. Anyways, a couple days ago I decided to finally get him a couple crickets. I got two small crickets and dumped them in his cage in the evening. I noticed he sat at the tallest branch in the terrarium and just kind of stared down at them for a long time. The next night when I went to change his food and water, I didn't see them so I assumed he had eaten them. But I found them sort of crushed next to each other under his food dish, like they dug under the bark and hid there together and died... it was really weird lol. But I didn't put any more crickets in and kept feeding him the diet. Since the crickets, he stays in a spot at the top of the branch all the time and doesn't hide in his usual spot anymore... and it seems like he is moving a lot less. Although I cant watch him all night, he used to be up and about by nine or ten o clock, but lately its like midnight and he is still up in the branch not coming down. I don't know if he really does move at night and has decided he likes this spot better? Or if something about the crickets scared him or something and he doesn't want to come down? I'm brand new to this so any help or advice would be really great. Thank you!