You do not need a bot to day trade. What the OP is certainly mentioning is related to day trading and usually if you have a strategy and you are making good use of it to know when to get into a position, when to stop loss and the fact that you should not be greedy and take with you the little profit you can while you still can due to the volatile nature of the market, the better.

A lot of traders however gamble and they call it scalping. They have no single strategy and all they just do is to buy the lows and expect a rise and in a case where the market keeps dropping further, emotion kicks in.