Hello
Is this snake harmful? It was by the door a few days ago and my husband herded under the fence. It has returned by the door agin? Should we call animal control?
Thanks

This appears to be an Eastern Ratsnake (formerly called Black Rat Snake), a very common visitor to suburban habitats and a great predator of pests like rodents to have in the area. They are non-venomous. While we can't see its markings and head coloration (especially from a side view) very clearly to solidify the identification, it does not look like either of our only two medically-significant snakes, a Copperhead or Timber Rattlesnake, since they have more distinctive features. Snake body patterns can change from newborns to adulthood as they mature, and it's common for Ratsnakes to be predominantly black as they age but still show some faint patterning from their youth, as this one appears to have.

You can leave it alone and don't need to call animal control; they are good to have around to lower the population of rodents, especially since some (like certain mice) can harbor Lyme disease transmitted by ticks. Granted, Ratsnakes can eat other small wild animals too, but simple baffles used on any bird nest boxes should be sufficient protection for them. The lump you see in its body is whatever it recently ate.

Snakes sometimes try to explore inside our houses as a type of shelter from cooling weather outdoors. Since it's not a great environment for their health, nor do most people want them inside, just make sure access points are well-sealed and doors are firmly shut and their weather-stripping and frames are intact. Ratsnakes are excellent climbers, so even vent openings that aren't secure higher up a wall could be access points for an individual looking for warmth.

If one does wind-up inside, a wildlife rehabber or experienced herp enthusiast ("herps" are reptiles and amphibians) living nearby can help to bring it back outside. (Local social media groups in that case could be a good way to find such a person, who will probably happily relocate the snake for free so it isn't harmed.) So you are not worried, be aware that if a Ratsnake is cornered and feeling threatened when someone tries to corral or herd it, they may feign a strike in self-defense, or bluff a warning by shaking their tail tip against the ground to mimic a rattlesnake. These are just tactics snakes use to try to discourage a predator when they are afraid and feel they must defend themselves; they aren't looking to bite if they can avoid it, and would much rather escape when possible.

https://extension.umd.edu/resource/snakes

Miri