How to Keep Ants Out of a Compost Bin Worm Farm

Develop several different strategies to keep ants out of your worm compost bin.

Opening your worm compost bin only to discover what looks like a million busy little ants scurrying around inside can leave you feeling as if you've got the proverbial ants in your pants. Although it's not typically a problem for indoor worm compost bins, ants often take up residence in outside bins, which can leave newbie worm composters scratching their heads as they try to figure out what course of action to take. Keeping ants out of a compost bin worm farm is simply a matter of developing the habit of monitoring and maintaining your compost bin regularly. If your bin does start to attract ants, you can stop them before they become a chronic problem.

Things You'll Need

• Spray bottle
• Water
• Window cleaner with lemon extract
• Paper towels
• 4 boards 4-by-4-inch
• 4 milk jugs 1-gallon

Instructions

1. Monitor the moisture level of your worm bin. According to the Santa Cruz County Department of Public Works, a dry worm bin attracts ants. Spray the top layer of bedding with a water-filled spray bottle. Stir the damp bedding in and continue moistening the exposed dry bedding until it's about as moist as a wrung-out sponge. Feel a handful of bedding to check the bin moisture level each time you feed your worms, adding additional moisture, when necessary, especially during hot weather.

2. Feed your worms the correct amount of food. Providing more food than your worms can eat results in having the food sit around longer in your bin, which attracts insects such as ants. As a general rule of thumb, 1 lb. of compost worms (about 1,000) can consume about 1/2 lb. of food scraps each day. Decrease the amount of food you give them if you notice old scraps of food sitting around in the bin for more than two or three days. Consider purchasing additional worms to start a second worm bin so you have an adequate population of worms for the amount of food waste you provide them.

3. Clean the outside of your worm bin periodically with a window cleaner that contains lemon extract. Spray the cleaner on a paper towel and wipe the damp paper towel across the outside surface of the bin to remove any scent paths that ants may leave after they discover your bin.

4. Raise your worm bin and install an ant deterrent. Purchase four 4-by-4-inch boards that are about 4 to 6 inches long. Cut the tops off four 1-gallon milk jugs and fill the jugs with 3 to 5 inches of water. Place the jugs on the ground, insert the ends of the boards in the jugs, and position the worm bin on the boards.

Tips & Warnings

• If ants invade your worm bin, resist the temptation to spray them with an insecticide because that can kill your worms.

References

• Composting in Santa Cruz County: Worm Composting FAQ
• Worm Farming Secrets: Worm Composting and Ants
• "The Worm Book"; Loren Nancarrow & Janet Hogan Taylor; 1998