Now that Summer has arrived and we may be spending more time outdoors, I make a mix of vodka and clove oil and put it in a small two ounce spray bottle that I can carry in my pocket to act as an insect repellent. It probably isn't as strong as commercial products, but it is probably much safer than some. I don't mind the smell of clove essential oil so this is fine for me. If I want to boost the repellent effect, I might add some peppermint essential oil to the mix. I use about 15 drops of clove oil per ounce of vodka. If I am going to add peppermint oil, I will just add 5 drops per ounce to the clove mix. This mix can also deter ants.
I make a similar mix using cinnamon and/or peppermint essential oil as an ant deterrent that I spray on food prep areas regularly until ants no longer appear.
A 50% saturated solution of borax will kill ants. I make a saturated solution then dilute it further with an equal amount of water and spray ants with this mix, which they then take back to the colony. If you make the solution too strong, the ants may not make it back to the colony.