Strange visitor "peaks" almost every day


in my piwik, i can see some strange flood of visitors, that means 25 or 30 or 40 visitors per hour, once a day - on a page that usually has about 1-4 visitors per hour.

that happens sometimes at 11 am, and sometimes later.

could this be a bug?

or could a search-engine-bot be the reason.

(it is always only 1 “real” visitor, but with dozens of visits within one hour)

(Sign in - Matomo)

thanks a lot