How not to track direct visits

I have spot that bots visits my website and its killing me,I get 20-30 visits per day mostly bots. Since the visits lasts 1-2s,that cant be human. Is there a way to disable direct visitor tracking and show only visits that comes from serp google/yahoo/bing/others + keywords used as it is right now.

If you do a “Reverse DNS” check on the IP, can you see if they belong to google, yahoo, bing, etc. ?