[thedoc (OP)]

Cassandra Walbridge  asked the Naked Scientists:
   
I live in Miami Florida where we are just going into summer and the rains have started.

Something rather strange is happening each night just outside our kitchen door on a tiled area that is well lit all night.

Each night as I step out there are thousands of fire-ants running around just in the area that is lit up. Very scary because they can give a very painful bite.

I tried putting out an ant-trap that consisted of a small container of a sticky poison that normally would attract the ants, but they were not interested.

However, each morning when I go out the door nearly all the ants are dead. This was happening every night.

The few that were alive looked like they were struggling to carry away the dead, but on closer inspection and observing there behavior they were in fact killing each other.

There were several survivors who were missing a few of their legs and struggling to walk or missing their antennae. And on even closer inspection there were thousand of tiny ant legs all over the area.

There seems to be an ant war going on. I have tried to follow them to their nest so that I can pour some of the syrupy ant poison in, but have not been able to find where they are coming from.

I have two Jack Russell dogs so have to be very careful about laying out or spraying poison and am very opposed to using insecticides. Can you please help and explain.

What do you think?

[CliffordK]

It sounds like a most interesting "battle" to watch. 

There is an article in Scientific American about Army or Marauder Ant Warfare.  If you have marauder ants, they may be transient, and hopefully have moved on. 

I assume there is different baits for different types of ants.  For our typical sugar ants, I just drop a bait container in their pathway, and they disappear fairly quickly.  It would be easy enough to cover your bait container. 

However, your battle doesn't sound like it is with a single narrow path.

[evan_au]

You may be on the border of two warring colonies of ants.

Ants will attack other ants who are recognised as being "foreign". This is not such a big thing if there is a small ant colony in your yard.
However, some ants like the Argentine ants form "supercolonies", where multiple colonies descended from a common ancestor all recognise each other as being "family", and don't attack each other. They just attack and destroy every other ant they encounter, allowing these supercolonies to spread out over hundreds of square miles.

But if the expanding ant boundary collides with another, equally large supercolony, the battle can go on for years, with the ant bodies piling up in the streets on the front line - but relative peace 100 yards behind the front line.   

Listen to 20-minute podcast: http://www.radiolab.org/blogs/radiolab-blog/2012/jul/30/ants/