I used to notice while playing on UB the short-stackers. They would almost never play a hand unless it was premium, and when they got that hand, it was all-in preflop. Every once in a while they would limp into a pot, but I would say 95% of the time, if you bet into them on the flop, min-bet or not, they would fold.
Like Dantigua was saying, as soon as they busted out, they would rebuy with the same exact amount every time, and if they won a hand, they would leave the table and go to another.
I know back when I played the micros on UB, you would have 3 or 4 bots at a table, and I swear they were all the same cheap/crappy program because they would all be a mirror image of one another. The funniest thing is that some are programmed to say something into the chat every now and then, mostly "nice hand" or "nice bet", but a lot of the times, it isn't a hand that you would ever say that for, like "nice hand" when the table folded around to the BB or something.
You can make money off the bots, but I would only call one of their bets if you yourself has a premium hand, because you can almost be sure that they do.