Hi there homesteadbound, I do not know if I would feed it to my beloved pet for sure. I know from working in a garden center that DE can be ingested by insects and the material clogs the digestive track and kills the little critter. I have a DE filter for my pool, the same concept! I never thought of using for the anthills and pop up all around my pool....hmmmm I will let you know.
Note: The box of DE used for filtering states that it should be used in an open area....DO NOT BREATHE THE DUST....your lungs will not be able to rid of it. Please be careful with the use of this product with animals. Especially dogs who want to sniff everything.