It was live. I will mention that I was dangling the mouse and when she would strike she would hit it but it'd get away. When it would escape and I'd pick it up and try again I noticed all this moverment stressed her out and she would strike with less force and recoil more. At first she would seem interested until she didn't get the thing, then she just seemed stressed with all the movement.
I really do think my 20 gallon long is a little crowded. To me it seems like unless I remove some of the housing in the cage she doesn't have enough room to really spread out or attack and constrict. It is great normally but I think it is a little too crowded for feeding.