It is a fairly common problem, a woman’s kitchen in Florida was being overrun by ants.  She made ant poison by mixing 3-4 parts honey with 1 part aspartame (Nutrasweet).  The honey was added to attract the ants.  The mixture was set out in a plastic saucer dish. The mixture lured the hungry ants who had been raiding her kitchen and within a few hours the dish was filled with dead ants.

Picture courtesy of Stephanie Relfe 2010 (www.Relfe.com)

As a follow-up, a small amount of the mixture was put on to the floor near the dish again.  Returning later it was a surprise to see that the ants had done something completely unexpected.

 Picture courtesy of Stephanie Relfe 2010 (www.Relfe.com)

You can see that the ants tried to cover up the aspartame likely as a warning to other ants from their colony to stay away from this potential toxic food source. You will notice that there are very few dead ants in the second picture. The ants quickly learned that the honey and aspartame mixture was a "poison pill". You can see in the first picture that there are also some bits of debris there as some ants may have realized the food source was toxic. The behaviour is the result of the aspartame that disrupts their foraging behaviours.  Ants can adapt quickly to avoid aspartame, so how do you deal effectively with an ant infestation?

Keep ants uninterested in your kitchen cupboards 

Remove or conceal  any food sources that may attract ants.  Ants are enticed by leftover food that remains on the surfaces in your home. Clean your kitchen by thoroughly by washing the floors, counter tops, and cabinets. Use equal parts vinegar and water for the best result. Do not leave food crumbs or food garbage lying around. Keep all food (including pet food) – in tightly sealed containers.

Find the point of entry and the ant trail they are using. The best strategy is to locate the ant nest, so when you see the little insects in your home, follow them back to the entry point. Remember that ants are tiny and can fit through even the smallest openings. Once you discover the entry points seal the holes with expanding foam and apply weather stripping under doors for tight seals.

Ant deterrent strategies

1. Chalk is the easiest and effective ant deterrent. Ants hate chalk, so all you have to do is draw a line around the room where you’re dealing with the infestation. They won’t cross the line, because the chalk dust sticks to their feet.
2. Lemons and lemon juice (in a spray bottle) squeezed or sprayed on the areas invaded by ants. Squeeze the juice directly in the holes or openings where you see ants coming through. Also cover the cracks in between the floor and wall, windowsills and any thresholds. Lemon juice is pet safe, and will leave your house with a lemon-fresh scent.
3. Baking soda will also stop ants. A line of baking soda is a good alternative if you’re out of chalk (they have the same ‘stopping’ effect). The ants will not cross this line, and the baking soda will also deodorize your house.
4. Vinegar sprayed in between the sidewalk cracks will deter ants, so spray it around doorways or other openings where you see the insets invading.
5. Boiling water to wash away the area. Either use a mop or wear gloves to scrub the ant trail to completely erase their scent. This remedy is something of as a natural antibacterial agent – but for ants.
6. Dilute beach in water 1 TBSP per bucket can be used to mop the area. The ants hate the bleach and it destroys their pheromone trails they have laid down to find readily available food sources. Mopping floors and wiping down door ways, and window sills where ants are crossing will slow them down.

Unfortunately these deterrent methods won't get rid of the problem and at best will only slow the progress of the ants searching for food sources.

 Infiltrating the Nest

So you have tried some (or all) of these deterrents but the ants are tenacious and keep coming back.  All your work will be in vain if you don’t destroy the nest. You could destroy all the ant trails and kill all the ants you see, but thousands of these insects are waiting in their colony. The next food crumbs that you leave out in the open will have the ants re-visiting for the free food.

The only way to overcome an ant infestation once they have established themselves is to wipe out the entire colony. Identifying the nest may be difficult if they have set up their nest along your house foundation wall.  Poisonous ant baits are the best strategy as the baits attract ants with a sweetening substance (mixed into the poison). Once they have had their fill, they’ll carry the poisoned food back to their colonies. Because ant bait is slow acting, the ants transport the poisonous substances back to their colony. Where they eventually die. Ant behaviour means that the poison is effectively recycled as the ants will cannibalize dead ants containing the poison.

The ant bait will take anywhere from 2 days (for small ant colonies) to 3 weeks (multiple large ant nests) to act. The effectiveness occurs as the ants will spread the borax poison themselves to all parts of their nest, including to the queen.

There are reports that aspartame when used as ant bait works for some species of ants but not all. Aspartame is not toxic to all ant species and some ants will actually thrive on aspartame-sugar or aspartame baits despite its low caloric value. For ants that quickly learn to avoid aspartame or find it non-toxic there is a better recipe.

Try this homemade ant bait recipe that contains borax crystals (borax is sold as a laundry whitening powder in most grocery stores).   

Homemade Ant Bait Recipe - Borax and Icing Sugar

Borax works by gradually killing the ants after they ingest it most ants bring back the mixture to their colony to feed their larvae and their queen. Using this borax bait will kill the ants and destroy the colony.

To use borax to get rid of ants in the home or patio outside, you can make the ant bait using borax and sugar. You will need:

• 2 tablespoons of borax/boric acid
• 1/2 cup of sugar icing sugar

Simply mix the borax with the sugar and  set out spoonfuls of the powder mixture on shallow plates where ants are frequently seen in the home, such as near kitchen counters and cupboards. The sweetness of the icing sugar draws the ants to this mixture, and it coats the borax.  The toxicity of the borax is the ingredient that kills the ants.  The mixture can be placed along entryways and paths that ants use to enter the home such as window sills, doors and any openings.

Another variation of the bait recipe includes replacing the icing sugar with honey:

• 3 parts honey
• 1 part borax
• warm water

Mix the three ingredients together until it forms a sticky paste. Apply this paste anywhere ants have laid down trails at entry points, window sills  or openings in to the house.

WARNING:  Make sure your pets don’t have access to the bait.  Borax like other laundry detergents is harmful to pets if ingested.

Using  this homemade borax-sugar recipe is a much cheaper alternative to spraying more toxic chemical pesticides. The recipe is an effective way to get rid of unwelcome ants in the house and it is also highly effective against cockroaches.