The partial albino Swift and its mate have built a nest. I placed some of the material in the box to get them started but they have added their own too, such as the small oak leaf, grass pieces and the occasional petal all gathered in the air. They will probably lay one more egg in 48 hours then incubation will begin. Swifts glue the nest materials together with their saliva. The nest is built onto a specially designed nest mould.