Hi Fran, Definitely mouse or rodent at the very least. Given that mice are the most common pests I'd say you found their 'highway'. I believe it changes color slightly as it ages (less bright when older) and visually not under UV it tends to dry to a blood color (ew).
Check for any fresh droppings along the trail too if you haven't already. And if you choose to clean this area, you can check it again a week later or so to see if there is any further activity. Best of luck! -Cienna Cienna Lyon-Lindholm (she/her) Preventive Care Assistant Historic New England Haverhill Center for Preservation and Collections 151 Essex Street Haverhill, MA 01832 ________________________________ From: 'Ritchie, Fran E' via MuseumPests <[email protected]> Sent: Tuesday, January 20, 2026 1:16 PM To: [email protected] <[email protected]> Subject: [PestList] Is this mouse urine fluorescing? Hello! I’d like to use the attached photo as a reference photo when training people on IPM. I think that it’s mouse urine fluorescing yellow under a UV flashlight. The fluorescing trail appears to be tracking from a crevice between the bottom shelves of abutting shelving units. I took the image 4 years ago when we had a mouse in our facility. We saw droppings in the area (they had already been cleaned by the time I brought in my flashlight, so I can’t confirm they were in the same spot). And the area smelled like urine to me. But I don’t have known mouse urine trails to compare this image to. What do you all think? Could this be urine, or is it more likely an unknown substance that happens to fluoresce? Thanks! Fran Fran Ritchie, Conservator (Objects) she/her Harpers Ferry Center [email protected]<mailto:[email protected]> American Institute for Conservation Professional Associate (peer-reviewed) NPS Conserve O Grams - Museums & Collections (U.S. National Park Service)<https://www.nps.gov/subjects/museums/conserve-o-grams.htm> -- This PestList and the MuseumPests.com web site are made possible due to the talent, intelligence, devotion and donations of hundreds of volunteers. Your donation to help this resource continue would be greatly appreciated. Please consider a donation donating at https://givebutter.com/MuseumPests To unsubscribe from this group, send email to [email protected] --- You received this message because you are subscribed to the Google Groups "MuseumPests" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. To view this discussion visit https://groups.google.com/d/msgid/pestlist/PH0PR09MB8777F3B6A2FE2F27D7948B09EB89A%40PH0PR09MB8777.namprd09.prod.outlook.com<https://groups.google.com/d/msgid/pestlist/PH0PR09MB8777F3B6A2FE2F27D7948B09EB89A%40PH0PR09MB8777.namprd09.prod.outlook.com?utm_medium=email&utm_source=footer>. -- This PestList and the MuseumPests.com web site are made possible due to the talent, intelligence, devotion and donations of hundreds of volunteers. Your donation to help this resource continue would be greatly appreciated. Please consider a donation donating at https://givebutter.com/MuseumPests To unsubscribe from this group, send email to [email protected] --- You received this message because you are subscribed to the Google Groups "MuseumPests" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/pestlist/SA2PR22MB2540A58AFAB8BD259600E13DDF89A%40SA2PR22MB2540.namprd22.prod.outlook.com.
