There are a lot of ways that population have developed over the years to try to kill off the fire ants they find in their yards. Pouring boiling water unto the mounds, mixing up homemade poison concoctions and other tricks are used by population who want to keep their families safe from fire ant attacks. However, most of these methods are thoroughly ineffective against fire anthills.
Killing the Fire Ant Queen
To kill the colony, there is verily only one way to succeed- you must kill the queen. Many homemade methods fail because they don't address this leading fact. Naturally putting something poisonous on a mound won't do that- the mound is situated the way it is in order to protect the queen. No covering poison is going to make it down through the many twisty tunnels that it would have to voyage through in order to get to the queen.
To kill the queen, you will have to come armed with something that is made specifically to stay with ants long adequate to infect her. The question with most homemade ant poison concoctions is that they are fast killers. They are not made to be tracked downward by hundreds of ants and to infect the queen that way. That's what commercial fire ant poisons are made to do.
These poisons are slow killers, allowing fullness of time for them to be tracked around the mound and to spread it to the other ants. If the poison is a particularly good one, it will have a food component mixed in. When the other ants find it, they will carry some back into the queen's accommodation to help feed her. This will kill her and the rest of the mound will die soon after her demise.
Using a technique like boiling water or a homemade poison compound may slow down the expand of a colony, but it is verily not guaranteed to do much more than that. To get them to work you may have to use them many, many times, and even then you may only get a false sense of security from them. It is possible, however, to use these methods on young mounds if you keep in mind that killing the queen is the extreme goal. Any poisons that you use should be geared toward a slow poisoning that will finally supervene in the contamination and death of the queen.
Killing Fire Ants