maybe thats the case. even items lying on the ground are pokeballs....Meh. PokeBalls are used to represent all those "lost items" that you find on the ground in the games. It represents a lot of things. Creators are just too lazy to design a mini sprite for every single one.
You do know that most bobbers look like Pokeballs right?
It's only natural that they'd replace the bobber with a Pokeball.
Well, it could be a special pokeball that has a way to make Pokemon attracted to it or maybe there is bait inside the Pokeball.why would a pokemon get attracted towards a pokeball, not a bait?