Cockroaches don’t get a lot of love. Scourge of humanity and seemingly impossible to eradicate, they and their forebearers have thrived for more than 300 million years.

Many scientists are fascinated by the creatures. Did you know they can produce their own antibiotics? Or that they can run up to 3 miles per hour? Scale that up for humans, and the winner of the 100-yard dash would be racing 200 miles per hour.

We humans, however, find them less fascinating when we spot a few in our homes, and with good reason.

A new study by U.S. and Canadian researchers shows that a common household pest, the German cockroach, produces endotoxins. These are inflammatory compounds from gut bacteria that amplify the allergic reaction to the roaches.

The scientists say a female of the species can generate 5,000 units of endotoxins through its feces daily. Multiply that by the thousands of roaches in a typical infestation, and homes are infested with millions of the toxins. That gets picked up by dust and distributed around a home.

Researchers collected roach poop from males and females to calculate how many of the toxins they produce. Don’t envy that job.

They also monitored 37 apartments, sorted between homes with and without infestations. Scientists tested dust from floors, in addition to heating and air conditioning filters.

The infested homes had many times the levels of roach allergens and endotoxins as roach-free apartments.

These results might help explain why cockroaches are one of the strongest risk factors for childhood asthma in low-income households.

So, don’t ignore a roach crawling in your kitchen — or the fact that you might be breathing its gut bacteria.