uns bots behaviour

I have a couple of questions regarding bots bids in general as well as for uns specifically. Feel free to point me to other threads if my questions have been replied to already.

Here we go....

1st observation:
Lately, whenever I put in a buy or a sell call for eg 20K uns shares there is immediately some 6 or 7 single shares before me in the queue. They weren't there before.
1st question:
It obviously doesn't do to much damage to my 20K call, but why is it that they are always before my call? Btw, I use EtradePro.

2nd observation:
I tried to try to make sense of the bot calls - basically trying to read which way they are trying to go or steer. Sometimes there are 20x495 share calls before opening. I have doubts about my analytical skills since I haven't found a pattern yet. I don't consider it a threat but rather a nuisance.
2nd question:
Does anyone have an idea what the uns bots are trying to do? Is it just some dumb programmer (of a broker firm that doesn't have to pay transaction fees) who has no idea about the business and forgot to turn it of?

Thanks for any answer
leo