Yes! Thank you! I couldn't find anything regarding it except for this one post...
First, here's a (not-so-)quick (but relevant) story:
Yesterday morning, my boyfriend and I were playing some good, old-fashioned, blind pick PVP matches because "why not?". Now, despite every single one resulting in the ally team's total annihilation, we kept on truckin' and got through maybe like, 6 or 7 in total and in literally every gd match, we had a bot on our team.
We picked up on this trend pretty quickly because all of them had acted in almost identical fashions to one another. Most often they'd do crap like hop from lane to lane entirely regardless of what was occurring in-game at the time; (as you had previously stated) they'd say absolutely nothing in chat plus never ping; and they would also be insanely aggro all game, and especially when at a time where it was a literal deathwish to attack them or turret dive or whatever. Not to mention, they always wound up feeding more than Grandma at Thanksgiving dinner.
For real though, we had a blind game in where there were 2 bots just on our team! It was Ahri and Viktor, who had both somehow ended the hour-long match with individual K/Ds of 0/25! Just the two of them were responsible for the enemy team having 50 kills and 0 deaths... Suffice to say, that one was just fucking ROUGH.
Long story short, we eventually just ended up going back to draft pick matches where there were no bots -- or none of the super obvious ones at least -- what-so-ever.
And oh, I almost forgot! All of the bots' summoner names were VERY similar, though appeared to just be some nonsensical gibberish. However, they aaaalllllll followed the same concept, such as: each name begins with 5 super random, case-alternating letters (i.e. upper- vs. lowercase) where the fifth letter in the sequence (always uppercase) is the first letter of a name.
I know that explanation was pretty poor, so here are some examples of how they look: "AiEoPeter" or "XwOeRobin" or "UvBrQuinn" etc.
Anyways...yeah. But honestly, I don't think Riot's even actually trying to find and ban these bots, and especially so considering that almost anyone could easily point one out in a crowded room.
(TL;DR) I'm so sorry this is kinda brutally long, but if you play blind pick much in Summoner's Rift, then be extremely cautious of anyone with a summoner's name like the examples above (the indented part). But if you don't really do blind that much...then disregard, I guess?