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These are the Madagascar hissing cockroaches and they're a common type of pretty much lab demonstration animal, so you see them in a lot of schools, people have them at home as pets, and then you also see them at zoos and stuff along those lines. You can go to a local store, pet store and buy them. They're not dangerous at all, people can handle them easily. The worst you'll get is they'll hiss when you pick them up, but that's pretty much all they do to scare off a predator.

(Roaches hiss.)

So they think there's a predator attacking them, so the whole colony is hissing. There we go, that's a good one.

We took the cockroaches and isolated them and determined that there are multiple species of fungi present on the cockroaches and that a lot of these are species that produce a lot of candida, which are spores that induce allergies.

So we got populations from pet stores, from other zoos, from personal home collections as well. We found that yes, there's fungi present on a lot of these and also, there has to be the tendency, if they're a really dirty colony, there usually has the tendency to have a lot more fungi present, particularly on the feces.

Pretty much the takeaway would be is that they're still good to have as lab demos, as pets, as stuff along those lines, but you've really got to be sure you keep them clean.

I mean, it still is a cockroach

It's common sense: After you handle a cockroach, you should go wash your hands. As long as someone goes and wash their hands, they'll be perfectly fine.

Research led by an Ohio State graduate student has yielded an unusual public service announcement: Be careful about handling Madagascar hissing cockroaches because you might be allergic to mold living on them.

The hissing cockroaches have been popular educational tools and pets for years. But the giant insects also have one unfortunate characteristic: Their hard bodies and feces are home to many mold species that could be triggering allergies in the kids and adults handling the bugs, according to the study.

"This is mainly a point of public awareness," says Joshua Benoit, a doctoral candidate in entomology who led the study. "We are not criticizing their use. We are just saying that if you handle these cockroaches, you should wash your hands when you're done."

Benoit and colleagues identified 14 different types of mold on and around this species of cockroach.

Madagascar hissing cockroaches thrive on dog food and fruit, reproduce plentifully, and do not bite. They grow to between 2 and 3 inches long and 1 inch wide, and will make their characteristic hissing sound if they are squeezed or otherwise feel threatened.

Benoit, an allergy sufferer himself, suspected the insects' large bodies and moist living environments might combine to create a prime breeding ground for mold.

Many of the mold species found on the body surfaces of young and adult Madagascar hissing cockroaches are listed by the Centers for Disease Control and Prevention as common indoor molds. For people who are allergic to molds, exposure can cause nasal stuffiness, itchy or burning eyes, wheezing, or skin irritation.

The researchers examined the insects from an Ohio State-based colony as well as those found in home collections, zoos, pet stores and science classrooms.

Ohio State's colony is housed in the university's insectary, based in the Biological Sciences Greenhouse Facility. The collection of live insects is a valuable resource for researchers.

"We have scorpions, spiders and colonies of many insects," Benoit said. "The resources we have here are fantastic. A lot of schools don't have this type of facility."

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