Last week, my son was awakened in the early hours of the morning by the call of an owl. I am convinced that it was a Great Horned Owl, which is the most common owl in Ohio (where I live). We double-checked the call that this particular owl makes, and the call matched the owl that he heard.
A few years ago, I found an owl pellet in my yard. It was a small pellet of fur and tiny bones and was very interesting to dissect. Great Horned Owls eat mice, birds, chipmunks, and squirrels.
I have mixed feelings about the owl that was heard. Apparently I have attracted it, due to the birds and squirrels that I feed.