Are there any animals with natural enemies on earth?

Any species on the earth has natural enemies, otherwise it will naturally be wiped out and affect the balance.

No natural enemies means that there are no species that can harm this species in the area where they live. It's called no natural enemies. There is such a bird in New Zealand. It looks stupid, round and can't even fly, but it lives well in New Zealand. Because there are no snakes or even cats in New Zealand, this kind of bird lives happily in New Zealand. It just eats and sleeps every day. If this bird had gone to other continents, it would have been extinct long ago.

In fact, the absence of natural enemies is just a false concept. No natural enemy can compete with this animal where you live. Just like in the sea, sharks are the most powerful. In the African savannah, lions are top hunters. If you really change places, if you throw the shark on land, it will die in a short time. If you throw a lion into the North Pole, it is estimated that you can't escape from the clutches of polar bears.

If there is really no natural enemy, it should be a water bear worm. Everyone has seen this creature in the sci-fi movie Ant Man. They are too small for us to see at all, but it is this creature that has almost immortality. It can't kill them at high temperature, and it can't do anything when it is cold. Even in vacuum, water bear worms can survive for a long time. In the environment where they live, the boss is out and out.

This nature is like this, there is no absolute perfection, only relative balance.