You are here:

Entomology (Study of Bugs)/Cocoon/nest on side of house


Bug nest?
Bug nest?  
My colleague sent me this picture and would like to know what insect might have made it and if it is a nest, egg sack, or cocoon?    It started out pink and then turned brown.

Thanks for your help.

- Peter


I am quite sure this is not an object of insect origin.  I'm not even sure that it is organic, though it might be a fungus, a slime mold, or other such organism.  It could be something oozing from the crack, like a sealant or foam insulation, or other material used in construction.

Thank you for reminding me that I should develop a library of things like this that are frequently mistaken for insect nests or cocoons.


Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

Awards and Honors
One of the top 50 experts in all categories for, 2009.

Past/Present Clients
Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

©2017 All rights reserved.