A non professinal suggests you use the little ant bait traps. They have an insecticide that will kill and entire colony when the little worker ants carry it back to home. I used triple expanding foam in tree cavity and put extremely fine stainless steel screen over the hole with it overlapped and held down on the overlap with downspout screws, Around the parimeter i used silicone clear caulk to seal the screen to the tree, I ended up painting the screen brown so it is less visable,, I live in nice area and silver maple tree is growing over the screen,, Why the screen? To keep the pesky tree sucking ants out, Even tho I have poisoned them seveal times,
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