Finding night critters using a black light

If you were to ask your kids what kinds of critters come out at night, they’d surely rattle of a list that included bats, owls, raccoons and other cute furry or fluffy stereotypical nocturnal animals.

The world of nocturnal critters is bigger than you think, in fact the other night while hiking in the dark I encountered toads, trap door spiders, salamanders and countless insects hovering in front of my headlamp.

The experience reminded me of all the night adventures my Dad use to take us on as kids. One of my favorites was an activity known to the entomology world as “black lighting”.

What is black lighting? Well, simply put it’s collecting nocturnal insects by using an ultraviolet light to attract them to a white sheet.

What you’ll need:

  • a white cloth (a bed sheet works great)
  • a black light (you can find these at party stores or usually in the lighting section of any big box store)
  • an extension cord, generator, or 12 volt battery with an inverter (something to power the light)

What you’ll do:

  1. Find the perfect location. Away from city lights is preferable, also try to pick a location close to water.
  2. Tie up the sheet between two trees so it hangs vertically like a curtain (or you can make a fancy A-Frame out of PVC like the photo above.
  3. Hang the light in front of the sheet using a tripod or another rope stretched between the trees the sheet is tied to.
  4. Center the light with the sheet and let it hang 1-2 feet in front of the sheet.
  5. When the sun goes down and it begins to get dark turn the light on and wait. You will notice bugs immediately starting to gather around the light and landing on the sheet.
  6. Some insects will fly around the light and land on the sheet, while others will land on the ground 5-10 feet away and crawl towards the light so make sure you check the periphery as well as the sheet.

You’ll likely find all sorts of cool moths and beetles, especially in the late summer (even more bugs if you live in a place that has a monsoon season). But keep your eyes out for other animals near the light, you never know what will wander in for a snack.

Why do bugs come to black lights?

It isn’t known exactly why bugs fly to lights, but it probably has something do do with the fact that nocturnal insects use light (the moon) to navigate. Because of this you’ll find that you get a lot more bugs at your light when you collect on cloudy nights or nights with a new moon.

3 Comments so far

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  1. You’re brave. I hate bugs. I’m afraid of bugs. I don’t want to see bugs – let alone attract them to me. Can my girls spend some time with YOU? LOL

    • Monique, Hahaa! Ya, if you don’t like bugs this is NOT the activity for you. Send your girls over any time, I’ll show em the ropes ;).

  2. Thanks for reminding me about this activity. It is amazing to do and I would recommend it to everyone.


    I'm Lindsey. I'm an environmental educator, my husband's a biologist. The outdoors is infused into everything we do; which explains why I'm better at mud pies than home decorating. More About Me

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