I just put 9 eggs under my Silkie yesterday. 7 of them are from my guinea pen ( My extra Roosters are in there too.) If my Guineas beat up on the Roos in there, what are the chances of these guinea eggs being pure or crossed with the Roos? I want pure guineas to hatch, and am thinking that they are so mean to the Roos that they'd never endure the Roos mating with the guinea hens. Is that reasonable thinking? I'll know in 27 days (or later) for sure I guess. Guineas are 28 days for incubating, right?