NO, this is an old wives' tale that is still widely believed by many a farmer. Guinea Fowl are among the noisiest, most obnoxious birds on the planet, and make a loud racket almost 24/7, which is widely believed to scare away snakes. Of course, this totally ignores the fact that snakes are DEAF to air-borne sounds and cannot hear this horrible cacaphony, although people sure can. I've watch Rat Snakes eat eggs right out from under a Guinea hen on a nest and the stupid bird was clueless(Guinea Fowl may be loud, and they are aggressive and will often attack people, en masse, if you accidentally get too close to their nest or young, but they are dumb as rocks when it comes to animal predators)and just sat there, watching ME. If a harmless Rat Snake could do that, a venomous Rattlesnake would have no problem getting past their defenses. I caught many a large Canebrake Rattler right in the backyard where my late grandfather kept a flock of Guinea Fowl to "keep away Rattlesnakes". My grandfather was also hard of hearing, by the way, hence his tolerance for what is certainly one of the loudest and most-constant animal noises anywhere on the planet.