Cuckoo
The common cuckoo does not make a nest of its own, and they do not bring up their own young. Instead, the female lays her eggs in the nests of other birds. Each female cuckoo specialises in just one host species, and lays camouflaged eggs in that bird's nest. For example, a cuckoo which lays its eggs in reed warbler nests will lay eggs that look like those of a reed warbler.