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Entomology (Study of Bugs)/bites on toddler only after using bathroom


My 2 yr old grandson gets 1 bite on the back of his leg/buttock with a huge welt that is red and hot and itchy when he uses his little potty chair on the floor. It is disinfected everyday. This has happened 3 times in 1 week. The bite is almost flat the next day but leaves a slightly dark circle and slight bruise. Benedry is given and cortisone cream applied for itch. The only bugs I have ever seen in there are these very tiny almost not visible bugs that come out from under the toilet and crawl on the floor but never out more than a couple of inches away. I have only seen 10 of them at a time and are not anywhere near his potty chair. No one else has been bitten.

Dear Linda - I hesitate even to guess as to what might be the cause of these marks; I can only suggest that the child be examined by a pediatrician for a medical opinion. There is a possibility that contact dermatitis rather than a bite may be involved.

Entomology (Study of Bugs)

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Ed Saugstad


Will accept most questions in general entomology, including those related to medical entomology, taxonomy, ecology, arthropod surveillance, and pest management. If you are requesting a 'mystery bug' identification, PLEASE either attach an image to your question, or post an image on a web page (such as Flickr) so that I can look at it, as verbal descriptions frequently are insufficient for a definitive identification.


21 years in the U.S. Army as a medical entomologist; duties varied from surveillance of pest populations (including mosquitoes, cockroaches, ticks, and stored products pests) to conducting research on mosquito-virus ecological relationships and mosquito faunal studies. Ten years as a civilian analyst for the Department of Defense, primarily on distribution of vector-borne diseases worldwide. Limited experience on surveillance of agricultural insects in North Dakota and Indiana.

Entomological Society of America, West Virginia Entomological Society, Society for Vector Ecology, National Speleological Society, West Virginia Association for Cave Studies.

American Journal of Public Health, Contributions of the American Entomological Institute, Japanese Journal of Sanitary Zoology, Journal of Economic Entomology, Mosquito News, and Mosquito Systematics.

B.S. in entomology from North Dakota State University in 1963, M.S. in entomology from Purdue University in 1967.

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