If you see a sudden spike in google analytics traffic reports, you may be surprised and wonder about the hidden magic. Actually, there is no magic going on, but it is caused by spiders and bots.
Spiders are nothing in real except computer programs which crawls your web pages for finding new content and indexing on search engines like google, bing and yahoo. There are different kinds of spiders like good and bad spiders.
You can exclude traffic coming from spiders and bots in google analytics. The simplest thing you can do is by visiting admin >> view >> view settings. You will need to tick the checkbox “Exclude all hits from known bots and spiders”.
To find out the spam traffic, go to the referrals report in GA account and sort the report by bounce rate in descending order. Check for the referrals with 100% or 0% bounce rate, they are mostly spam referrals. Read more about fixing spam referrals.