Bird that cannot raise their own offspring

The reason why I made this video was because I hate this bird, even I know it is their nature. Sometimes, I don’t even know why clock inventors use the sound of this devil bird in their clock alarm. I do pity the small bird (reed warbler) which works very hard to build their own nest and then has to feed the devil that kills her offspring. This is not the only bird that behaves in such way. There is still a kind of duck which leads the life in similar way. However, that kind of duck is not that cruel. They will just leave the eggs for other birds (gulls, usually) to lay and when the baby duck (chick) hatches, the chick will just leave the nest after a few hours without bothering the bird nor their offspring. That is acceptable behavior and not to be hated. Watch the Cuckoo and think for yourself. MPSINFO