Do bots have opening books?

From experimenting with the bot Maximum (Level 25), if they do, they appear to only go for 8 moves or so , e.g. in a Sicilian Dragon game with me playing Stockfish moves:

The last book move by Black (Komodo25) is 7... Bg7 . Besides that, Komodo25 missed a mate in 16 starting after 19... e6 .

Thanks, although I thought they might make an exception for Komodo25. Komodo25 makes a suspect/dubious/busted choice of 8... a6 in  the opening Sicilian Defense: Open, Dragon, Yugoslav Attack, 7...O-O 8.Qd2 . The position after 8... a6 is shown in this diagram:

I call it dubious because it has bad W/D/L statistics according to opening explorer, and because Stockfish 14.1 evaluates it at +1.62 at depth 40.

I was glad to get my first unassisted win ( some memorization, some calculation), vs Komodo25:

wow

r/chess reddit admins told me the oppisite when i pointed out that it felt like under 500elo players feels like im playing against bots alot of times. Not gonna pretend i know anything about chess, but they said that the average player is 1200 elo, but at the same time the average player is well above 1200 bots, which makes no sense to me, that implies something wrong with the whole elo system, which i can hardly fathom but  before i could ask them to clarify, removed the post i cant even view it now. I was pointing out how i struggle to play against 300elo players yet can beat the 1200 bots reliably, still struggling to beat a 1300 bot. Ive had games where they where playing perfectly into an early queen and retreat, then suddenly just start hanging pieces left and right 2 minutes toward the end of the match. I just realized this topic is really old, sorry im just lurking in the forums.

Bot ratings are estimates and unless they are in a pool of other players, getting their ratings adjusted after wins/losses, there's no mechanism to get them to a more accurate rating.

Engines are designed to always try and find the best move in a position. It's actually kind of hard to make them dumb down in a realistic way.

That makes sense to me.

Computer engines have an evolutionary approach to complex problem solving.
So if they seem to have a preferred opening, that's simply the result of millions of iterations proving to the system the superiority of that opening. It's not preprogrammed.

With emulative bots like the Danny and Danya bots there are of course preprogrammed lines based on the actual player's preferences.