Glowing scorpions and unusual observation techniques

Last year I attended a lecture on arachnids and a guided night hike and found out that scorpions glow under UV light! This is probably common knowledge for many of you…but it blew my mind.

Of course we did what any self-respecting naturalists would do - borrowed some UV lights and planned a night hike to look for them again. For anyone else that didn’t know scorpions glow here’s one that we found and photographed with normal flash and again under the UV light https://www.inaturalist.org/observations/109535011

It occurred to us that most people wouldn’t think that borrowing UV lights and going hiking in the dark to look for scorpions (and hoping for snakes, spiders and tailless whip scorpions) is a normal evening activity.

I’m interested to hear about your unusual observation techniques; the things that you do to search for inat observations. Bonus points for things that are relatively simple and inexpensive for me or anyone else to do. If I didn’t know about them glowing under UV light I never would have gone out looking for scorpions which makes me wonder, what else am I missing that I could find with a simple change in approach, equipment, timing or environment?!

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I don’t know if what I do is unusual, but I go into the rainforest at night, turn off my headlamp or torch and just sit there. It’s amazing what you can sometimes see and hear. I do this quite a lot and often don’t take photos or sound recordings, it’s just something I enjoy doing (and there really is a lot to see and hear). I have a few observations of bioluminescent fungi but I don’t really do it to get a photo or an observation, I do it for the pleasure it brings me. In Papua New Guinea I sat for maybe four hours several times watching the fireflies and didn’t once reach for my camera; I just enjoyed it. To answer the question: 1) a tripod; and 2) not record at all, just observe (that’s good enough for me a lot of the time)

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  • Check trees and plants for diseases and parasites.
  • Wave a net around in weeds and you will find a ton of different arthropod species. Doing the same in a creek will often get you arthropods and small fish even if you can’t see them.
  • Put a bright light or a UV light shining on a white sheet on warm nights and it will attract lots of insects.
  • If you can swim and there are clear clean water bodies near you, basic snorkelling and underwater photography gear is not that expensive and it’s such a cool experience, a whole different world under the surface.
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I actually bought a small UV light to look for scorpions in my yard when I lived in TX.

Within the past year or two, I learned I can use that same light to look for flying squirrels!

Scientists discover that flying squirrels glow bright pink under UV light (bgr.com)

Should be worth pointing the UV light at everything. Might make a new scientific discovery.

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I’ve wanted a UV light for looking at blooms and moths. Flying squirrels like to hang out in one of my elevated stands, I’ll definitely be trying this!!!

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Does the UV light affect the animals you shine it at?

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Some can see it, some cannot. Other than that, not especially.

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I just got a UV to check for which arthropods might be found with it (by active searching, not attracting). I new that scorpions glow - but there are none around where I live.

Coolest find so far: Earthworms!
With a UV light, it becomes clear they belong to the Oligochates: green rows of glowing bristles are well visible, in addition to a deep purble intestine trakt makes these common worms suddenly very exciting to look at

Other than that, galls and mines as well - but I would describe my search pattern more broadly: Recognize a plant, then think about (either by knowledge, experience or assumption) which animals might be associated with that plant - pollinators, parasites (miners, gallers, aphids…), herbivores etc.

Also, I have a bat detector - less so for the flying mammals, but rather for concealed orthopterans

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I mostly use a UV light to look for the spots where my cat peed around the house… thanks for the reminder that I really should take it out to the yard every now and then! I heard that hemlock woolly adelgid (of which I have plenty on the hemlocks around my yard) and its predatory beetles fluoresce in different colors under UV. This time of year might be a good time to check for that. Flowers are said to have patterns that show up only under UV light.

Another technique I’ve heard about that I might try on my own lawn this summer is “tick dragging” - apparently popular enough to have its own wikipedia page.

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If you go shine that UV light on trees and rocks you will find fluorescent lichens as well. They’re everywhere (and at all times of year)! Often they look identical until you observe them fluoresce and realize that some of them are different species, https://www.inaturalist.org/observations/108776308

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I helped lead a UV light walk last night. Not too many flowers out, but we looked at a few that had cool pattersn on them, and found fluorescing lichens, pill bugs, lizards, and leaves. It’s pretty cool. You never know what shining a UV light on something can show you…

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It has fascinated me for a long time, I have a lot of photos: https://www.sunguramy.com/p465770871
BBC nature has a nice program about UV light and such as well, i forget which one but it was on netflix you may like it. David Attenburgh of course as narator.

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we often have to snorkel for cave surveys of aquatic life, that is always fun going underground suited up for that (I’ll never cave dive though - I have friends who do, and I still think they’re mad)


(yes i can swim, but the neoprene float vest is a) warm and b) stops me from stirring up silt since i can float around rather than ‘swim’)

Another thing is using a headlamp to look for spiders at night, those shimmers aren’t droplets of water, follow them and find the spider! (also fun to tell your arachnophobe friends :P )

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Its not clear how damaging the UV is to critters. I never expose live things for more than few seconds.

And I allways wear safety glasses if doing long exposures.

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My friend thought I was crazy the first time I took her for a desert botany road trip and told her to bring a swimsuit and snorkel. We visited some large springs and surveyed them for snails in between rare plant sites.

I’ve helped with surveys for toads and most people walk quickly, shining the flashlight around to find them but I found it much more effective to walk slowly and listen. Toads are slow and kind of clumsy so they make a lot of noise moving through dry grass and leaves.

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Fluorescence isn’t just a property of living things. My primary use for UV lights is for minerals. Lots of minerals fluoresce including calcite, fluorite, corundum, and hyalite opal. Different excitation wavelengths produce different colors as well, and some can even phosphoresce as well as fluoresce (btw, fluorescence and phosphorescence are different for those who aren’t familiar with the terminology. Fluorescent minerals only glow when the UV light is shining on them and stop immediately when the light source is removed. Phosphorescent minerals continue emitting light for some time even after the excitation source is removed.) This may apply to fluorescent organisms as well, so you might try using multiple UV wavelengths when you’re out searching. Btw, if you’re ever in the area, you can look along the shores of Lake Michigan, you can find lots of fluorescent rocks colloquially called ‘yooperlites’ (Actually just a sodalite-rich variety of syenite). Easy to find and neat to show people.

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Florescence is common in a range of arachnids, I use my UV mostly for harvestmen, but also some spiders. But specie to specie even within a genera there seems to be a wide range of how much they glow. Also some seem to only fluoresce after a moult (At least it seems that way). Its quite good for flatworms locally as well.

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Neat, I’ve been wanting to do this. I’m thankful not to have an abundance of scorpions (that I’m aware of at least). But I see a lot of millipedes and centipedes in the daytime when I’m gardening so perhaps there will be enough glowing critters to make it worth my while.

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I used a uv light on the diamond in my engagement ring it was passed down in my husband’s family. The diamond glowed blue. This means it most likely came from South Africa.

slow is so key
me caving normally: point a to b in 10 min
me in same cave bioinventory: point a to b in 2 hours

I can’t use my ears though, i noticed that walking with a friend who birds. I have bad hearing loss. I never can find birds as I have no audio clues of where to look. They are the hardest thing for me to find, actually, since it seems like zoning in on where they are hiding amognst the branches needs hearing, or you get too close without seeing them and they fly off, and process starts over.

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