I am an Entomologist with Texas AgriLife Extension Service and have many years of experience trying to manage fire ants. If you have fire ants in your home you need to treat the problem outside. The ants live in your yard and migrate into your home looking for food. The oils that were applied inside your home will not harm your child. Many of the essential oil based products are not required to be registered as insecticides since they are food based. Washing your carpet will remove the oils and they will no longer work against the ants (if they worked to begin with).
If you want to use organic products outside the home I would recommend using a bait containing the ingredient "Spinosad". This is an OMRI (approved for use in organic production) registered bait that is very effective against fire ants.
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