The small to large herd (or pack) of males perusing a bar, searching for female stragglers (away from their group) or lone targets. Just think of a pack of coyotes and their hunting methods. Except being filled with booze.
Jane: Do you see that group of guys there? Some of them are kinda cute.
Jill: Yes, be careful. That's a guyote herd. Don't go to the bathroom by yourself. Take someone with you. And don"t wander too far from the bar either!