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What's an Ant Moat and Why Do I Need One?

Updated: Nov 1, 2020

Ants are one of the most common and easily recognized critters of the insect world. They are found pretty much everywhere in the United States. In fact, there are over 1000 ant species in North America alone. As an insect group, ants, have important functions in our ecosystems from cleanup to excavation, pollination to collection and the creation of additional habitats for other creatures. Their main job is one of keeping and maintaining a healthy balance in the natural world and they do this by foraging for many types of food resources during the daytime and nighttime. The food they find and collect is taken back to the colony nest, distributed and or stored for later use. As ants forage about, they leave an invisible trail of pheromones for other ants in the colony to follow once a food resource is located. The more ants that use the trail, the more pheromones and the more prominent the trail becomes to more ants. This behavior of foraging and leaving pheromones for other ants is what creates problems for Hummingbird Feeders and other wildlife feeding stations. Especially, since ants appear to have a sweet tooth and they will go to great lengths to get at the sugar water in Hummingbird Feeders. Anyone who has a Hummingbird or Oriole Feeder knows that once ants have beaten a pheromone path to the feeder, they are almost impossible to fool or deter. I've tried moving my feeders to different tree branches and locations on porches or stands only to have the ants return in a day or two. Hummingbirds, for their part, do not like ants. Once ants have found the feeder, they crawl onto and into the feeding ports and either die by drowning or float on the top of the nectar. The presence of ants in the nectar, now contaminates the feeder and the birds will refuse to use the feeder. So, what's the trick to keeping the ants out without using pesticides, playing musical locations, or taking the feeders down altogether? The answer is a tool called an Ant Moat or Ant Guard (not to be confused with the pesticide laden "Ant Guard" trade marked by Perky Pet), The Ant Moat works by serving as a barrier or guard between the ants and the feeder, it's easy to use and works like a charm. The Ant Moat is hung above the feeder and once the ants can't cross the moat or guard, they stop coming to the feeder and go away. Ant Moats come in many styles, price ranges, colors and materials. The Ant Moat featured above is a double) ended hook made of copper with a small 3/4 inch cup (moat or guard) in the middle for holding water, mineral oil, ground cinnamon or *diatomaceaous earth.

Opinions vary depending on what works best and where one lives, but many birders report their best results with a small amount of mineral oil to coat the inside of the small cup ant moats. Others prefer only water or a small amount of water with mineral oil floated on the surface of the water to reduce evaporation of the water. The mineral oil has a dual function: the oil reduces evaporation of the water and it has a lower surface tension than water. Thus, ants that could walk on water, fall through mineral oil.

Some sites suggest using food oils (olive, corn, canola, cinnamon), shortening or petroleum jelly (Vaseline) in Ant Moats. We find these products have a tendency to dry out, get tacky and collect dirt which, eventually, allows the ants to travel across the moat. Also, ants, like Grease Ants, are attracted to food oils, shortenings and lard as food resources. Consequently, beware of using food products in or on your feeders. Coating wires and hooks with these products is not recommended, since the oils drip off and or collect dirt rendering the parts passable to ants. I have also seen where some Hummingbird sites recommend using petroleum jelly or mineral oil around the feeding ports to keep ants and bees away, but this is a big No No! Leaving any kind of oily or sticky substance on the feeding ports means the Hummingbirds could accidentally get the substance on their beaks or feet. An oily or sticky beak is a big problem for a bird and it puts their ability to groom and maintain their feathers for warmth and flying at great risk. When birds can't fly, they can't find food or care for their chicks and the birds become easy prey for other predators. Accidentally eating the oils can weaken, sicken or kill the birds. It is important to remember that the goal of having a feeder is to help feed the Hummingbirds and not put them at risk. Always consider the size of the ant moat, the location of where you plan to use it, the weather and possible risks to the birds. Water is always the safest for the larger moats/guards as some users are multi purposing the moats/guards as bird drinking cups. The smaller ant moats can use water as well but some users report better success with coating the inside of the small cups with mineral oil. Whatever your purpose or preference, always consider possible risks and check your feeders often.

Now that the behavior of ants and their desire for food resources is understood, we can take steps to discourage ants from visiting Hummingbird and Oriole feeders. There are many types of Ant Moats or Ant Guards, so the decision becomes one of deciding what will work best for the type of feeder, location, size, weather, time of year, purpose and type of ants. What deterrent is used inside the moat or guard may also be determined by environment. Whatever choice is made, keep in mind safety, check the feeder often, keep the feeder clean and always, enjoy your flying jewels!

Happy Birding!


*"Diatomaceous earth – also known as D.E., diatomite, or kieselgur/kieselguhr – is a naturally occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder. It has a particle size ranging from less than 3 μm to more than 1 mm, but typically 10 to 200 μm. Wikipedia"

Here is a good link to information on Diatomaceous Earth by Happy DIY Home on brands and uses for pest control:

Diatomaceous Earth can be purchased at Home Depot in the Natural Pesticide section.

Do not use the Diatomaceous Earth used for pool filters since it contains high levels of added crystalline silica that can harm the lungs of humans, pets and wildlife. Use only "Food Grade" Diatomaceous Earth.

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