Good job on not handling him...is he just striking at it but not actually grabbing it?
If so, I notice mine do this when they are mad..or just want it away from them. Like when I tried feeding my mouse eater a small rat...he snapped at it a million and one times...okay maybe twice...but when I placed a mouse in there he ate it on the first bite....ths also happens when I get a rat that is larger then they usually eat...maybe this new rat was a little larger then the last?

Or maybe he's just not hungry yet....keep us posted and good luck.

~Audrey