Identify and Report Bots When You See Them
For those of you who don't know bots are players who use third party programs to queue their accounts in coop vs ai games to automate farming ip (and xp when leveling, this is a plague for low level accounts, check other posts for more). The program will traditionally chose ghost and heal for summoner spells and after sparsely buying some items they will go to the mid turret and wait for the minion waves to start. They'll then begin farming and using a rigid combo pattern the whole game if they even use their abilities and make little to no attempt to survive or run from trades (they'll pretty much feed in order to not be flagged as afk). To throw you off from suspecting their not bots they'll also buy items without using them to complete an end item build (if they buy anything at all) and will also randomly say things like push or help (just a basic one word comment).
If you see these tell tale signs and you want to confirm your suspicions try and talk to the supposed bot. If they respond to non of your questions properly (like even a half retarded human being can) then their definitely a bot and you should report them after the game so riot can eventually punish the account when these reports pile up.
If the fact that this violates the way riot intended the game to be played is not enough for you to report or your still generously believing their not a bot ask yourself this, "why would anyone pay attention to a game their intentionally feeding in? Also why feed in a game where the AI opponents are so easy to beat and trick?". This is a lazy method of farming ip and/or xp that does nothing but burden players who are actually playing (since the bots rely on accounts with actual players in the game to win and earn them more ip/xp) and make a game that should be an easy and fun learning experience difficult.
To report bots (for anyone who hasn't used this function at all) you wait for the end of the game when the post game stats window to open. Look for the player name and the champion that was picked in the top-right section of the window. There should be a thumps up icon (used for positive reinforcement of player behavior) and an exclamation point (!) which you can click to report a player for doing something unfriendly or unsportsmanlike. For reporting a bot you check the Cheating box for using third party programs. Any supporting evidence you can provide like screenshots or anything you can describe goes a long way in helping riot punish the offending account with anything from a warning to a temporary or permanent ban of the account from play.
I want to thank those of you who read this far (walls of text can be annoying) and know in general these players who are botting deserve no pity for doing this. I've played online games for a long time and I can safely say that the majority of the players who take this route in online gaming are a combination of lazy, trolly, and toxic when they're actually playing in competitive pvp (be it normal or ranked) and drag down the game in their own selfish ways if things don't go their way.
In summation, please always report a bot when you see one. Riots only reliable method of punishing an account is discovering repeat offenders from player reports.