Is my sentence proper?

The tree height acts as a first barrier that a predator has to pass, but if it pass it, a predator will face with stinging wasps as a second barrier.

Thank you for your response.
face the wasps or come face to face with the wasps.

Not face with the wasps.

Why are you calling the predator "it". Is it a robot?

if it/he passes it.

Sorry, I can't understand what you mean. Emotion: sad In English , we use it for words like child, cats, and a predator.
For example, the bird builds its nest on a tree close to the wasps' nest.So, the height of a tree is a first barrier for the cat and if it(a cat) passes it( the barrier), it ( a cat) will face stinging wasps.