Let’s face it. There are many reasons to avoid bird poop. Breathing dust or water droplets contaminated with avian droppings can cause a flu-like illness. Salmonella is another danger. And who hasn’t been irritated by a bird’s classic signature on the windshield or hood of their just-washed vehicle?

Add this to the list: antibiotic resistance.

Scientists at Rice University in Houston had the unenviable challenge of examining the droppings of urban ducks, crows and gulls. They found that these critters’ poop carried opportunistic pathogens that harbored high levels of genes that encode antibiotic resistance. These bad guys include bacteria that can cause a range of ailments, from urinary tract infections to sepsis and respiratory infections.

Now, you might think, it’s not as if I’m going out of my way to come into contact with bird poop, or for that matter the droppings of any other of God’s creatures. But the Rice researchers note these antibiotic-resistant genes and bacteria can be unwittingly ingested by humans through swimming. In addition, it might be hard to spot bird poop while, let’s say, gardening. And scientists say the droppings can persist in the soil up to an inch deep for many days.

What surprised scientists, and what is frankly kind of frightening, is that the levels of antibiotic-resistant genes in this urban bird poop was comparable to what is found in the fresh feces of commercial, antibiotic-fed poultry.

So, if you’re cleaning up bird droppings or working in areas where it might be present, be sure to thoroughly wash your hands or any exposed skin. Or just steer clear of those white splatters. Danger lurks.