天敌 (tiān dí): predator; natural enemy

On the African savanna, the relationship between lions and zebras is that of predator and prey; lions often chase zebras to fill their stomachs.

Mice are naturally afraid of cats because cats are their natural enemy; as soon as they smell a cat, they immediately hide in their holes.

Teachers and cheating students are like natural enemies; teachers always try every possible way to prevent students from cheating on exams.

In business competition, these two companies have become natural enemies; they fight each other for market share, and neither gives way.

The natural enemies of mosquitoes are dragonflies and bats, because dragonflies and bats hunt mosquitoes in the air.

In this office, Xiao Wang and Xiao Li are natural enemies; they always disagree and often start arguing over trivial matters.