Direct entry traffic increase

I noticed an increase in direct entry traffic which averaged to 20-40 visits a day.
For the last two days it was 146 and 280 respectively. I checked visitor logs, and found various IPs, different countries, OSs, plugins, ISPs. It’s always to the home page. Some continue browsing, but most end their visit on the home page.

I wonder if there is any situation where it is actually not a direct entry but somehow Piwik is not recognizing it. I haven’t noticed this on my other sites.

Thanks

An update:

I see webmasters talking about direct entries from all over the wrold since February this year. It looks nobody was able to figure it yet. It looks like human traffic but it’s not.