For Roaches & Most Other Insects
½ C sugar
½ C flour
½ C Crisco shortening
½ C powdered boric acid
NOTE: Do not add any liquids of any kind.
For Ants
1 TBS boric acid
1 TSP of Sugar
4 OZ water
Cotton balls
(see the instructions at the bottom)
Temperature:
NOTES ON BORIC ACID: get as close to 100% pure as you can get. Usually you'll find a container that lists 99% of the active ingredient as Orthoboric Acid (aka boric acid) — don't just get another product that "contains" boric acid. You can usually find it at most any grocery store in a 24 or 32 ounce plastic bottle, listed as a roach pesticide… just check the label. Boric acid is safe to use around pets and humans as it takes a whopping huge amount of it to do any damage to large mammals at all.
Boric acid by itself is one of the most effective agents used as a pesticide — it's a mild corrosive to organics, although safe to use on pretty much any surface, and a desiccant and that's eventually what kills the insect… dehydration and dissolution from the inside. By itself is only partially effective as it relies on an insect to walk through it and ingest it when it cleans itself — but if you add it to a mixture that will attract insects, then that's a whole other story.
The concentration of boric acid in these Roach Cookies is higher than in any other insect baits you can buy, and is therefore more effective. Just mix all the ingredients together thoroughly, making sure that it can hold its shape when pressed into a vessel, about the consistency of chocolate-chip cookie dough. Usually I use those cute little waxed paper Dixie cups folks buy to put by the bathroom sink for kids to use. I cut the cup to leave about ½" of the bottom as a shallow dish and press the cookie into that, level with the top.
Place these against walls and in corners wherever it seems likely that insects will walk or live — pantries, cabinets where food prepared, and under every sink are a few good starting places, but don't be shy about overdoing it a bit. You can even mix a little more Crisco into the batch and roll the cookies into balls that you can then roll into inaccessible places like behind the fridge, under the stove and dishwasher. You can also take this thickened cookie and smear it into places that are hard to get a cup or ball into as its pretty sticky.
This stuff should be good for up to about a year, as the Crisco keeps it moist and "edible" and naturally, the more rancid it gets, the more the bugs like it. After that it gets stiff and brittle and should be replaced with a fresh batch.
For specifically treating ants: mix the boric acid, sugar and water in a bowl. This can be poured over a cotton ball in a small dish or bottle cap. Keep this from drying out for continued effectiveness. Place Cotton balls in path of ants.
That's about it. After a few weeks you should notice a decreased amount of critters roaming about, with fewer as time goes on. Boric acid is effective on cockroaches, palmetto bugs, waterbugs, ants, silverfish, carpenter ants, termites, fleas and a whole bunch more.