Catch Mosquitos, Flies, Hornets and More: 3 DIY Bug Traps That Actually Work

The transition from late summer to fall is one of the best times of year. The temperature cools off but is still warm, making it an ideal time to be outside on the deck, porch or garden. But that idyllic late summer afternoon can quickly sour thanks to flying pests. Considering temperatures are still high and the fall season doesn't begin until next month, you'll likely still be dealing with irritating or even dangerous insects for another several weeks. 

Some bugs like fruit flies and gnats are just plain bothersome. But, crossing paths with stinging or biting insects like hornets and wasps can result in serious pain or harm. And that means you may need to be proactive about keeping them away from your home. 

You can go to great lengths to fend off these pests, using combinations of sticky traps, buzzing electrical contraptions, lawn treatments or sprays. Having lived most of my life in the south and midwest, I've used many of these off-the-shelf insect traps and repellents. However, in my experience, few things work as well as easy-to-make DIY bug traps. Below, I've detailed three different trap styles and a variety of options for bait, starting with the easiest one first. For more tips, read the right spot to put your houseplants to keep them alive, how to grow vegetables without a backyard, the scientific reasons behind why you get so many mosquito bites.

The Best Bug Sprays of 2023 See at Cnet

1. Mason jar trap

This trap works great for small flying insects like fruit flies or gnats. It's also the easiest of the three to make. Most any similarly sized container will work, but here I'm using a small, wide-mouth mason jar with a metal lid. 

Take an awl or sharp-pointed scissors and punch a few small holes in the lid (adult supervision warning). Alternatively, you can instead cover the jar with plastic wrap and secure it with tape or a rubber band. 

For bait, pour in some apple cider vinegar with a few drops of dish soap. The soap will cover their wings and weigh them down so they can't escape the jar. If you're feeling generous, use beer instead of the vinegar and send them out in style!

Useful against: Fruit flies, gnats

Cost (minus bait): $2 to $5 

Tools needed: Sharp-pointed scissors, knife or awl

2. Plastic bottle trap

The most versatile of the three options is the plastic bottle trap. You've probably seen examples of it. You can use any rigid plastic bottle that narrows to an opening at the top. Two-liter bottles are most commonly used for this kind of trap, and that's what I use here to demonstrate. 

Just before the bottle narrows, cut off the top. Invert that piece back into the bottle and secure with tape or glue. The trap will sit as is, or use a piece of wire or string through holes you would put in either side to hang from a tree or hook.

The trick here is bait. You have many options. In all cases, to help keep from trapping desirable honey bees, avoid using honey and try adding a splash of vinegar or a piece of banana peel.

For mosquitos

Take a quarter cup of brown sugar and dissolve it in a cup of hot water, then add a little dish soap. If available, you can add a gram of yeast for an extra punch, but the sugar water itself should work just fine. Works best in shady dark areas. Consider covering or painting clear plastic.

For flies

Bait with a mix of water with fruit-scented dish soap. Try adding decomposing fruit in place of sugar.

For hornets and wasps

Assuming the murder hornets haven't gotten us all by the time you read this, start off in the early spring with a base of water and dish soap. Go for a protein base and add cooked meat grease or mashed up fish (the murder hornets may demand a whole steak). 

Once summer hits, switch to a 50-50 sugar-water base with dish soap and sugary additions like apple cider vinegar or other fruits mixed with vinegar. Place in a sunny, well-lit area.

Useful against: Mosquitoes, flies, hornets, wasps

Cost (minus bait): $1 to $2

Tools needed: Scissors, tape or glue

3. Wooden carpenter bee trap

Male carpenter bees aren't generally a threat to humans, but stings by female carpenter bees can happen, and the small holes they can make in your outdoor wooden structures can be annoying. Other than treating or painting your decking or whatever wooden target they're attracted to, this trap is the next best way to get rid of carpenter bees. 

Pick up a single untreated cedar picket from your local home store (or use similarly dimensioned wood you already have laying around). The picket I am using is six feet tall, five-and-a-half inches wide by five-eighths thick. Starting from the bottom of the picket (avoid the dog-eared end), cut six pieces that are each 10 inches long, and one square piece measuring four and seven eighths inches.

The smaller piece is the bottom, where you will drill a hole to fit and glue a bottle cap. The other pieces make up the four sides and two for the overhanging top. Use any small nails or screws to join the pieces. You can add a hook to the top for hanging if you like, otherwise just use a piece of string or wire.

Use a half-inch drill bit and drill holes into the center of the bottle cap as well as at least two sides of the trap. The holes should be near the top of the structure, angled upward. The bees should find their way into the bottle and not be able to make it out. Pull the bottle out to discard whole (don't unscrew and let the bees out!), insert a new bottle to start over. 

Useful against: Carpenter bees

Cost (minus bait): $4 to $6

Tools needed: Drill, saw, glue, screws (or hammer and nails), drill bits: one half-inch, one same diameter as bottle cap.

For more gardening tips, check out my recommendations for starting a vegetable garden, for killing honeysuckle and for growing your own herbs at home. 

More tips for your yard and garden

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• The Easiest Method to Remove a Tick Is One That Doesn't Require Tweezers
• What Determines Hydrangea Bloom Color? An Expert Breaks Down the Science
• DIY Compost Bin Step-by-Step: Build a Worm Farm to Reduce Waste
• You're Planting Trees All Wrong