For most of us, what happens in our sewer lines is a case of “out of sight, out of mind,” but once you see this photo, tweeted out by whoever runs the social media account for San Antonio Water Systems, which delivers and maintains water and sewer services to many residents of San Antonio, it’s hard not to think about what else might be slinking around in those underground pipes. 

The photo depicts a big honkin’ Great Plains Rat Snake, chillin’ out, maxin’, relaxin all cool on a fairly large swathe of tunnel. For those worried about the SAWS employee who snapped the image, you’ll be relieved to hear the photo was taken by the “small, tractor-looking robots” that explore the tunnels with cameras and water hoses to clear away blockages (though when the Singularity happens, those robots will probably be freaked out by these missions). 

According to, the giant snake isn’t the only thing that SAWS ‘bots have found while maintaining the tunnels, either

Other items that have been photographed in the sewer include turtles, rats, roaches, a basketball, a toy car, car parts, grease, baby wipes (to name a few).

The sewer lines are typically six to eight inches wide but can be as large as 64 inches, said Anne Hayden, a spokeswoman for the agency.

Many of the items end up in the sewer from being flushed in a toilet or through valve openings throughout the city, she said.

It’s unclear from the photo just how big the snake chilling in the SAWS tunnel is, but Great Plains Rat Snakes tend to grow anywhere from 3-5 feet, and this one looks like he’s probably on the larger side. At least we know that with this big guy roaming the pipes, there are fewer rats scurrying around down there.