Strange visits from amazonaws.com

Hello,

I’ve got a strange kind of visit every time I post something in my blog.
No bandwidth used, but statistics shows this data: from US, Cambridge, 72 visits, 72 page views, 72 hits, and 41 visitors, or something like this in other posts (same number of visits, page views and hits, and less for visitors). I discovered they come from address like this: ec2-18-223-156-1.us-east-2.compute.amazonaws.com, but the IP changes.
I don’t want something like this on my statistics. What can it be?
I’m not sure that blocking 18-IP addresses is the solution.
What can I do?
Thanks