Hummingbirds are entertaining, cute, amazing fliers and all that. For my part, though, they are not as beneficial as the usual prey of a Preying mantis is harmful. So I'll continue to welcome the mantis and hope he makes more meals of the numerous and very damaging differential grasshoppers. If numbers increase the odds of a grasshopper being a meal rather than a hummingbird, then the adult mantis probably has reached adulthood via many more meals of grasshoppers than of a hummer. Nature can be beautiful, fascinating and just plain odd. It isn't always a choice between good and evil, but often some of both. Brown water snakes are certainly beneficial where their diet consists of invasive cane toads, but they are pretty efficient at nearly eliminating my resident toads which I welcome. I'm sure the drought conditions have caused the surge in their population since I have water and toads. Normally I don't eliminate non-poisonous snakes, but the almost complete disappearance of toads at the house combined with an aggressive personality has made the brown water snake an exception. Probably if it ever starts raining on a regular basis, the snake population will disperse so the impact wouldn't be so great. At least that's what I think. I don't doubt a mantis is capable and opportunistic enough to grab a hummer for a meal, but I'm really skeptical that hummingbirds make up a significant percentage in the diets of Preying mantis.