Pet Doors In West Texas–Good Idea Or Asking For Trouble?

With a perpetual ZOO at my house--we're considering adding a Doggie door to the back door that lets out into the backyard... It's a completely fenced-in backyard with locked gates and a 5-foot privacy fence, so we aren't particularly concerned with a person necessarily being able to, first of all, get over the fence, and second of all, being able to crawl thru the door when we aren't there... (I'm sure there are cases where this has occurred but with the house being at the end of a subdivision and facing a main highly traveled street, we aren't that concerned. Plus we have cameras).

We're WAY more concerned with the non-human critters who could possibly get thru the door, since when the slide-lock panel is off, all that holds the plastic flap in place and closed is a magnetic strip. It does do a really good job of grabbing the flap and holding it in place-but I'm not sure it would hold up in one of our infamous West Texas storms (we'd more than likely be home or have the slide lock panel closed in those instances anyway)... But even though the plastic flap DOES take somewhat of a good push to open, we're concerned about snakes and scorpions being a factor. Do YOU have one of these at your house, and if so, how well has it kept unwanted critters OUT?

That's a photo of the door that's currently on the new back door we're installing, and we're going bigger since we have a Lab/Pitbull/Cattle Dog mix who won't fit thru that opening... Comment below and let us know what you think--Good idea or not, and if not, why?