They march across the back of the neighbours house, along her gate, across the fence, along our gate, along the side of of our house, across the front and down the side to the fence where they disappear into the 'good' neighbours place (Good fences make good neighbours. When we put up a huge non-see through fence they became much better neighbours!)
The highway is usually about 10cm to a foot wide and, as a general rule of thumb, that where they stay. I'm guessing that all the rain has upset them and in the last month or two they have been coming across our verandah, not the front of the house
When you have visitors to the front door, its quite a sight.
Over the years we have sprayed 'em with everything money can buy but are getting worried that its actually affecting us more than its affecting the ants. You spray them, they all die, you clean up 20 million tiny black bodies and within the hour, you wouldn't think you had even had a go at them. They are back in the same quantities as before - the missing 20 million or so making no apparent impact of any kind!!!
I researched the net extensively and started my battle in earnest a few weeks ago...
Here's what I did...
First I accepted that I wasn't going to be able to find and kill the nest as we think it is on the neighbours neighbours place. I wanted to move them from the front door and verandah back onto their age old path across the front of the house.
With that goal in mind, I got a jar of Vicks vapour rub and created a simple barrier across the path that they were using. It worked a treat. Then they walked around it. Knowing it worked, I then extended my barrier all the way to the ceiling and down to the floor. They didn't like either the smell or the texture and kept their distance.
Then I started spraying a mixture of Eucalyptus oil and tea tree oil diluted in water on the inside of the verandah and around the door hoping to kill those that were trapped in there already and to deter those who weren't with the smell. Apparently ants don't like strong smelling stuff - pepper and cinnamon were also cited but I didn't know how to get them to stick to the walls!
This worked. For a whole hour or so and then they were back. After a while I discovered that you can just kill them by spraying them with water. You don't need chemicals at all. If you have an ant invasion in your kitchen for example and want to kill them, just use a fine mist and spray them and then simply wipe them up.
I spent the whole day spraying the verandah at 1/2 hourly intervals and by four o'clock, I was ankle deep in little black bodies - they just kept coming. They do not learn quickly! The verandah, however, smelt like the inside of a Eucalyptus would!
I kept up the spraying with diluted Tea tree and/or Eucalyptus oil in water for a week. Eventually they more or less gave up. I actually think I have driven them inside the ceiling of the verandah but at least they are not crowding around the door and frightening off my visitors.
I now have my bottle of spray sitting on the verandah so I can pounce on the if they break the barrier and before they establish their path again.
In a case like this - simply making it too hard for them, consistently, is the way to go. They need to be trained that this area is no longer safe and not to come back. The Vicks barrier is still working. Full of dust and other bugs now but the ants wont go near it..it must smell too much for their liking.
Good luck if you have ants on a large scale!
Green-ness: Petty green in that I'm using natural chemicals not man made concoctions.
Frugal-ness: Much much cheaper than proprietary spays or insecticides
Time cost: You need to be dedicated with this sort of invasion... Lots of time needed at regular intervals.
Skill level: Just point and spray.
Fun -ness: Not much at all - I prefer to live and let live normally...