What does it mean by saying "coyotes, picking off the weak members of the herd"?

[Joeyy]

What does it mean by saying "coyotes, picking off the weak members of the herd"?

MONICA: [...] I mean, I bring a guy home, and within five minutes they're all over him. I mean, they're like- coyotes, picking off the weak members of the herd.

PAULA: [...] As someone who's seen more than her fair share of bad beef, I'll tell you: that is not such a terrible thing. I mean, they're your friends, they're just looking out after you.

From Friends S01E03

 

[GoesStation]

Re: What does it mean by saying "coyotes, picking off the weak members of the herd"?

Coyotes are predatory canines. One way they hunt is by stalking a herd of deer; they attack the weakest deer and kill it ("pick it off"). They hunt other herd animals the same way.