To quote the old man, "pretty weenie".

I mean, c'mon, if you were in some joint and someone said we're here about rats, would you get up and run out? And it didn't exactly ruin business; the people who left had already paid for their drinks, so no harm done. And the two pranksters didn't stick around, so all they had to do was wait for the bar to fill up again with new customers and it would be business as usual.

The gag of them all was Norm and Cliff reading poetry with the signal override. And I busted up at Norm's "drinks are half price at Cheers if you say 'Gary sent me'".

(Sidenote: I guess two guys portrayed Gary over the years.)