Click anywhere to throw a poke ball. If a poke ball touches a Pokemon, it gets caught. Once 14 out of 4 Pokemon have unfortunately been caught by rusty, zapdos will appear. Also you can catch a few shiny bidoofs on the way. WARNING: MAY CONTAIN DYING POKEMON. IF YOU ARE SENSITIVE, DONT PLAY, but otherwise, you're fine.
Big thumbs up to Dorkly and the Pokemon rusty series.