I've heard and read stories about flocks of guinea ganging up on, and escorting coyotes off property...ganging up on and attacking foxes, dogs, even cats that come near a flock of chickens they were raised with. Our main reason for getting guinea fowl is for the warning system...our dog doesn't bark unless he's heck-bent to get at something he's been given permission to chase (like the coyotes last night)