Spending a lot of time on his belly

[Zero138]

the last few days dexter has been eating and pooping good but he has been under his hide on his belly with his legs, all four, sprawled out. h can walk and everything just fine, any ideas?
hes 2 months old
hes about to shed his tail and he has recently been switched to slightly larger crix. but he is pooping a lot still so i doubt impaction any ideas?

 

[AprilMayJune]

Sometimes they get grumpy and irritable when they are about to shed or when they are shedding.