It may not be news that cockroaches cause allergies because of their feces, saliva, and bodies, but the Madagascar hissing cockroach poses additional allergy threats, as Medical News Today reports.

Unlike the household pests we detest, hissing cockroaches have enjoyed the status of educational tools and even pets for many years. Reported to be gentle (whatever that means in an insect), hissing cockroaches are large enough to ‘pet’ and emit intriguing sounds for which they're named.

However, these cockroaches harbor and create even more allergens than their less-revered cousins – mold. Researchers have identified 14 types of mold on and around hissing cockroaches, housed in their hard bodies and feces. Many of these molds are associated with allergies, and others may cause secondary infections if they enter the lungs or an open wound.

Lead author of the study, Joshua Benoit of the entomology department at Ohio State University, states, ‘This is mainly a point of public awareness. 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.’ He also advises that the cockroaches' cages should be cleaned regularly to avoid the build up of feces and exoskeletons, favorite homes to these cockroach-induced mold allergens.

However, it may be best for allergy sufferers to avoid the temptation to befriend these moldy cockroaches altogether.