Elaphe obsoleta lindheimeri
The Texas Rat Snake is the largest snake found in Harris County, and can reach lengths of over six feet. When newly hatched they are about 9 to 11 inches long and have a light gray background with brown saddle-shaped blotches running down the back and an arrowhead-shaped pattern on the top of the head. They change color as they grow, however, and the pattern of adults is more subdued. The background color of an adult Texas Rat Snake will range from shades of brown to yellow and even orange, and the blotches are much less distinguishable in adult specimens. The top of the head also changes color - adults' heads are slate gray to black on top and white underneath. This color scheme is an accurate identification method to use, because they are the only large snake in the Harris County area that has a head that is gray-black on top and a lighter colored body that has dark saddle-shaped blotches on the back.
As the name implies, the Texas Rat Snake's primary diet is mice and rats, causing them to be commonly seen in any place inhabited by rodents - including human homes. With this in mind, it is easy to see that the key to keeping this type of snake away from or even out of your home is to control the rodent population. I have occasionally released large Texas Rat Snakes into my attic to control field rats that have come in to the house from neighboring woods, and have never seen any of them again. Either they find the rodents, eat them, and crawl out from wherever the rodent came in, or they don't find the rodents and leave because of lack of food. Either way they are a great form of natural rodent control. Also, if you were to encounter a Texas Rat Snake in your attic and it bit you, all that is needed medically is to washed the area thoroughly with antibacterial soap and water - they can hardly break the skin. However, if you had mice or rats in your house, you don't even need to come into direct contact with them for them to make you sick. A rodent could crawl into your kitchen and come into contact with a piece of your food. If you were to eat that food, there are a number of diseases that can be passed from rodents to humans in this way. You decide what's better - rodents or rat snakes!