yea for a 2 y/o bp even 3 or 4 months isnt really all that horrible.. you have nothing to worry about
this time of year he probably thinks hes gonna get some lol and no need to switch to live yet if you do and he starts eating regular again you will have to switch him back to f/t which probably wont be easy just offer it less often like every 2 weeks so you waist less rats.. he will eat and if he gets hungry between offerings you will know by his behavior