You are here:

Entomology (Study of Bugs)/Tiny black bugs on wood deck


QUESTION: I have had many itchy bug bites on my legs, feet and waistline for over 2 weeks and I continue to get more. I thought they were chiggers biting me from working in the garden, but there are now almost no weeds at all in my garden and I am still getting bitten. I have never had chiggers in my life so I thought it was odd in the first place to be getting all these bites. I will note that this is only the second summer I have lived in this house in Iowa though I have lived in this area my whole life. Today I was standing barefoot on my wooden deck and noticed my feet start to itch. I looked down and my feet and legs were covered in tiny black bugs. I had my hand on the railing and my hand and arm were also covered in black bugs. I looked at several places on my deck and the railing and there are bugs everywhere. The attached pictures aren't that good but if you can see them you'll notice the bugs are small but visible. The envelope that the bugs are on was laying on the deck for less than 10 seconds before acquiring all those bugs. Can you please help me identify these? Are they the continual cause of all my bug bites? It's like they appeared out of nowhere. Thank you!

ANSWER: Dear Chris - I cannot see any identifiable features of the tiny critters in your images, but anything that small would just about have to be a mite of some kind. That aside, it is extremely unlikely that they would be chiggers (larvae of mites in the family Trombiculidae) - see for details.
  As there is no way that I can offer a definitive identification, I suggest that you use a moist toothpick or similar object to place some of them into a small container of rubbing alcohol, and take them to your county office of Iowa State University's Cooperative Extension Service - see for links to contact information. Someone there should be able either to assist in identification or if that isn't possible, forward the specimens to the appropriate university office. It is altogether possible that these may turn out to be a non-biting species, and that the source of your bites lays elsewhere.

Hope this helps,

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: I ended up having these bugs identified by Iowa State University. For anyone interested, it turns out they were black pepper mites (also known as bird mites) that were living in a bird's nest underneath my wood deck. When the baby birds left the nest, the mites left in massive numbers and scattered themselves all over my deck looking for more food. The mites cannot feed on human blood but, although harmless to humans, the mites can cause lots of bites that are extremely itchy. The university recommended a chemical spray containing cyfluthrin, such as Tempo, to get rid of the mites.

Dear Chris - Thank you for letting me know. Because the bird/rodent mites that I am familiar with usually are semi-transparent to brownish in appearance, I didn't think of mentioning that possibility when you described yours as black. One thing that I really enjoy about fielding questions on this forum is that I usually wind up learning a lot in the process!
Thanks again,

Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


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.

©2017 All rights reserved.

[an error occurred while processing this directive]