Passive voice to describe food chain

Snakes are eaten by eagles.
This is a passive sentence.

へびは、わしに　たべられます。

Eagles eat snakes.
This is an active sentence.

​わしは、へびを　たべます。

I was praised by the teacher.
This is a passive sentence.

わたしは、せんせいに　ほめられました。

The teacher praised me.
This is an active sentence.

​せんせいは、わたしを　ほめました。

I was bitten by a dog.
This is a passive sentence.

わたしは、いぬに　かまれました。

A dog bit me.
This is an active sentence.

​いぬは、わたしを　かみました。