from what ive read - mix some borax powder with some powdered sugar, they
take it into their nests and eat it and get food poisoning. interestingly
borax is used in some French caviars, but despite its use as a pesticide its
LD50 is similar to that of table salt. I still wouldnt wanna eat it though

in regards to ant control with aphids im hoping a circle of borax-sugar
around each rose bush will take care of the resident ants and allow more
predators to get stuck into the aphids

its probably safer to use borax-sugar than something like Ant Dust, but then
Ant Dust is probably more ant specific so wont kill as many other insects,
so im not sure what the best option is