ganjati

1. (+ acc.) to chase; to run after
   Pas ganja mačke po celom dvorištu. — The dog chases the cats all over the yard.
2. (ganjati se) to chase each other; to play tag
   Deca se ganjaju po parku ceo dan. — The kids chase each other around the park all day.
3. colloq. to hound; to chase after
   Šef me ganja zbog izveštaja od jutros. — My boss has been hounding me about the report since this morning.
   Ceo život ganja pare. — He's been chasing money his whole life.

In the sense "chase each other" it is used with se.