I initially got into moths courtesy of my house’s outside lights. I’d been photographing everything living thing I encountered to put on iNat, so the moths that congregated at my lights each night were a particularly tantalizing target. Before I knew it I was hooked and ordered a black light to try to attract more. These days I still keep that old black light running during the mothier months, but I’ve stepped up my game in a number of ways.

This post is about a couple of common techniques to attract moths that works for both home and travel:

1. Light sheets
2. Light traps

(See this post for a third, less-travelled technique: pheromone traps)

1. Light sheets

The basic idea here is to shine a light against a reflective surface (usually a sheet), then make a stiff pot of coffee and try to stay awake as long as you can to see what moths show up. It’s a lot more work than light traps and if you have a day job it’s often infeasible, but it’s by far my preferred way of observing moths. You see the most species this way, it’s more fun and probably less harmful to the moths.

People have different preferences for sheet setup and choice of size. I personally do this: tie a rope between two trees at around 5-6′ high and hang a full-sized white bedsheet over them, one side long to the ground and the other fairly short, then affix it with clothes pegs. I then set up the light to focus its light in the centre of the sheet, and, well wait! Typically I set up 2 sheets, a little distance apart, facing different directions – ideally edging into slightly different microhabitats. You get a surprisingly different set of moths between the sheets this way ¹.

Wind is a problem – having the sheet flapping away makes it hard to see the moths and hard for them to settle – so setting it up in a wind-free area is always preferred, but sometimes not possible. On windy nights I weigh down the bottom of the sheet with whatever’s around. At home I have a few bricks on standby, but when travelling I throw a couple of heavy branches over the bottom of the sheet. That’s usually enough.

Note that moths will land on both sides of the sheets, so be sure to have easy access to them both. Also, with the sheet hung over one side you’re going to find the insects manage to wedge themselves into the crease. This is fine – I actually quite like to see what it gathers. If it’s a particularly moth-heavy night I sometimes shake it empty.

The downsides to relying on trees is obvious: they’re often not where you want them. It can often be difficult finding trees that are the right shape, size, with an area clear of debris and so forth. Because of this if I’m planning to set up sheets at an unfamiliar location I go well in advance to scope out the best spots. Otherwise dusk comes on fast and you’re stuck without a spot. It’s not ideal, but by and large this approach works for me.

Regarding lights, at home I have a pair of outdoor black lights (marketed for parties – I’m not joking) which I plug into the wall and angle the lights to shine up on the sheets, but when travelling I use my lepiLEDs (see below).

2. Light traps

I know I just said sheets were my preferred way to catch moth, but using light traps turns every morning into Christmas morning. It’s always a huge rush to see what you’ve caught!

There are all sort of light traps available, some homemade, some for sale. But they all work on a similar principle: the light attracts the moths which fall into some soft of chamber where they’re unable to escape. Collectors typically use a “kill trap” but I use a simple net which I check in the mornings, then photograph and release.

I exclusively use LepiLED traps (Maxi). These are lights designed to emit light at the wavelengths most favourable to moth. They’re lightweight and easy to pack around and last a long time (~7 hours) on decent powerbank batteries. Depending on the night and available habitat, I set up to 4 traps.

My kit involves the following:

• a stand, from which to hang the light and net
• a sign I leave on the ground explaining what the heck is going on & try to discourage anyone who stumbles upon it from stealing my gear (or at least feel crappy about it when they do)
• the light + plastic funnel
• a net which hangs underneath the light and funnel to catch the moth
• Some powerbank batteries. I have a couple of different types, but these are the best I’ve used so far. They’re fairly fast to recharge (I can recharge 4 over the course of a day in a hotel doing just 2 at a time. Originally they lasted up to 7 hours for the Maxi LepiLED but I should re-check that… they’re a bit old now. There are probably newer, more powerful ones now. #progress
• egg cartons, lining the bottom of the net to provide a place for the moths to hide after being caught.

For the stand, I use screw-in-the-ground bird poles from a nearby birding store, Wild Birds Unlimited. They’re designed for bird feeders, but they work equally well for the 0.00001% of the population who want to hang moth nets. Advantages: you can position them pretty much wherever you want. Most ground is screwable, but the stonier spots can be frustrating. Disadvantages: all told it’s 2 metal fitting poles, one metal arm, one piece of metal that screws into the ground, so it’s not especially light. When you’re setting up 4 traps a night, you can’t carry them all at once and it’s a bit ungainly even carrying one set. So typically I find locations that are close to the car + can do short sorties to get them all set up.

Egg cartons in the net was a depressingly amazing discovery, which I only learned about 2 years after using the nets. Sigh. Big thanks to the book Much Ado about Mothing for this tidbit, but apparently everyone knows about this and I’m just a chump. The egg cartons provide places for the moths to rest after being caught and vastly simplifies the job of extracting the moths in the morning: a single 2×3 egg carton can house dozens of moths which you can pull out, view and photograph very easily, plus it saves you enough time so you don’t get fired for coming in late to work each day. Depending on the time of year I can add anywhere from 6-20 2×3 egg cartons to the bottom of the net.

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That’s pretty much it! I’ll furnish this post with some photos at some point.

1. This study is worth a read. It examines the strength of moth lights vs volume of nets in terms of catchment size and found that volume trumped light strength. That’s why I typically set up multiple lights each night – usually 3 or 4. I’ve consistently found them to catch different things – this is true for both lights and sheets. ↩︎