Yes, sometimes. Often, no. Mine did for months. The guineas had been in the coop in a nursery area for months, since they were 4 weeks old and the chickens were six months old. At four or five months, the 'terrible teens' for guineas, my alpha male suddenly attacked my smallest RIR hen. Anytime he saw her, he'd attack. She began living in the nests. Then it progressed to my other two RIR hens. No other hens were bothered. In fact, the hens would often break up fights between the guineas. I locked down the guineas for two weeks. During that two weeks was when my rooster came off quarantine and was integrated into my flock of girls. When I released the guineas, my alpha began making rushes toward the rooster. Hawkeye could handle Dodger one on one, but then the other three guineas began attacking from all sides. They bodyslam their victims, not like chickens at all. Finally, after one day when they ran my rooster off into the woods and he refused to come back till I came to get him, I said enough is enough, and I rehomed them with someone on BYC. I miss them, though. They were extremely tame and sweet with us.