Boric acid is non-toxic to mammals if consumed in small quantities. In small amounts, it should pass through your system without harm. If using as a pest control in a home where animals are present, we recommend making a bait and putting it into a place where your pets cannot eat the material. Powder can be used for pest control with pets in the home if it is used in places where the animals will not get it on their feet/bodies. Animals which lick themselves / consume too much boric acid will possibly experience gastrointestinal symptoms.
To use boric acid in pest control, the idea is to get the pest to eat it, and their bodies will dry out, thus killing the bug.
Cockroaches / Dry Application
Cockroaches clean themselves every few seconds. Boric acid powder can be lightly placed on surfaces where cockroaches are found. They will run over the boric acid powder, clean their feet, and then die from consuming the boric acid on their feet. Do not apply too much as bugs can detect the boric acid and may avoid it. Granular boric acid does not work well for this application. It must be powder. Baits can also be made (see ants)
Ants / Bait Method
An ant problem is no problem for boric acid. Mix the granular or powder boric acid with sugar, roughly at a 5% or less boric acid concentration. Too much boric acid can repel the insects. In the case of ants specifically, higher concentrations may be used. Next, add small amounts of water to make it into the texture of a paste. Apply the paste around areas of where ants / pests are found. They will eat the bait and then die. Ants will carry the bait back to the colony and the entire colony will die. In most instances, ant colonies can be wiped out in a matter of hours.
Other bugs which clean themselves regularly, are not in the larva stage and do not have piercing mouthparts may be eliminated using boric acid. Boric acid will not kill bed bugs or bugs which feed on blood or plant juices.