Mud Tubes on Your Wall? Meet the Spider Hunter.
Found mud tubes on your wall? They belong to Mud Dauber wasps. Learn why they hunt Black Widows and why you probably shouldn't spray them.
You walk out to your patio and see them. Long, ugly tubes made of dried mud stuck to your brick wall or porch ceiling. It looks like someone threw clay at your house.
These are the nests of the Mud Dauber Wasp.
Don't Panic
They look scary. They are long, black, and have a weirdly thin, stretched-out waist. But honestly? They are the chillest wasps in the world.
Unlike Yellow Jackets that swarm and attack in a gang, Mud Daubers are loners. They don't have a hive to defend. They rarely sting unless you literally grab one.
The Horror Inside the Tube
Before you scrape that nest off, you should know what's inside. It's actually kind of cool (and gross).
The female wasp catches spiders—specifically Black Widows. She paralyzes them, stuffs them into the mud tube alive, and lays an egg on them. The baby wasp hatches and eats the fresh spiders.
So, if you have Mud Daubers, you have fewer Black Widows. It's a trade-off.
How to Remove Them
You don't need poison. Just wait until winter (when they are empty) or use a paint scraper to knock them down. Wash the muddy spot with water and a scrub brush.
Pro Tip: If you see round holes in the mud tube, the wasps have already hatched and left. It's just empty dirt now.