sometimes its a hard a work to follow guineas around and around all day long looking for their nests, and finally you got nothing, but what i' can say is, a nest is usually a generally hidden spot,in thick grass,bushe's,or other tall vegetation that may provide a good cover, its a depression scrap on the ground lined with grass or unlined, if your guineas are cooped let them out in the early noon if they don't lay in the coop, as you open the coop you may notice that females are always in rush,follow her but following guineas isn't easy, you need to be very snaeky like a fox, make sure she don't she you following her,but locking her in the coop until she lay her egg is a good idea, lock her every day ar 6 days, and let her out until she lay an egg, as she lays in the coop she may forget her old nest, i' wish you a luck"