I believe I'm feeding him enough but you may be right. They are small rats that he's getting fed and I try to wait until he poops before I feed him again so maybe I should just be more consistent and just feed him once a week regardless of him pooping.
And I dont think he's sick, but his star gazing has gotten more frequent, which may be causing the "hissing" if it is something in his respiratory system.
Thanks for your help!