I guess ever since Twisted treeline got removed, the bots migrated to other game modes, but holy shit, there's literally an ARMY of them. They're already infesting AI games and starting to show up in regular ARAM and blind pick games. When is this madness gonna end?
There's no more "dead" game mode you can just dump them into, Riot. This is a problem you'll have to eventually fix sooner or later.
It's not hard to differentiate a bot from an actual player. They usually always have some really weird rune set that make zero sense, like PTA on a Nunu or Comet on Master Yi. They don't talk in chat, even if you directly talk to them. They literally run past enemies without looking at them. This is beyond what a "bad player" would do. As a matter of fact, I played Pyke, and the bot in my team kept the "cut" gold in his inventory for the rest of the game, never consuming it lol.
This pre season is already aggravating enough for a lot of the playerbase, this isn't another problematic issue you want to have on top of it all.