You can't get an exact answer as to why but if the pattern is every second and it repeats so hard that it becomes impossible to do it manually then it is a bot but what is the reason behind doing it?
- Price manipulation: Sometimes a lot of fake buy and sell orders are created to affect the price.
- Trading strategy: to test a certain point, so if it is not achieved, the position will be closed.
- Swing trading: bots are characterized by speed and sometimes the differences between trading pairs are profitable.
- Technical error: Not likely, but if it is rare, it may be.
There may be other reasons.
Yes, exactly. There can be many reasons why the bot is always taking second place in order books. As pointed out above, this could be simple price manipulation or price testing. Since, these are very technical gimmicks that only a handful know, we can only speculate.
What's certain is that nobody is manually doing any of this and I suppose the take home message is that you it is not your manual limitation - it is set up in a manner to always follow a specific pattern.
Best to do is be aware and if possible use a different exchange so you don't get caught up in this manipulation.