Hummingbirds eaten by praying mantis

This is not a question but more a warning. With 25 feeders in our front yard we attract many hummingbirds but this year we had a tragic experience. We found a praying mantis on the hummingbird feeder with a adult female bird in her claws. She was feeding on the hummingbirds’ brains and then dropping them and waiting for another. As I know that mantises are very beneficial I did not kill it although I felt like it. We removed the offending insect and checked very carefully twice a day. I am tell eNature readers about this unfortunate incident so they can be watchful. I had never had this happen before but once was enough. If I had not have been so discussed by the sight I would have taken a photograph. And "YES" it was a huge female mantis.