Before setting off on the road for a new batch of auditions on the ITV1 reality show, Piers had revealed: "I'm hoping we will find some great animal acts."
However, auditionees Caz and Judy failed to match his expectations when they took to the stage in Manchester and claimed to have a group of dancing ferrets.
"It's quite well known that ferrets can do the weasel war dance," Caz revealed, "if you wave anything at them they will go berserk."
Judy, who owns 107 ferrets, added: "My family think I am mad, but I don't care, I just love ferrets."
Rather than performing a "weasel war dance" as promised, the ferrets instead decided to make a bid for freedom and had to be collected by hosts Ant & Dec at the side of the stage.
Simon Cowell complained: "Unless I am missing something they weren't dancing, one tried to mate the other and the rest ran off, it just fell apart, didn't it?"
Britain's Got Talent airs on ITV1 at 8.05pm tonight.