How do I make DIY ant spray for use on my basil plants?

Put cornmeal around your basil. Ants are important to the environment, but when they get intrusive inside or out, it is time to remove the colony. Here is a safe, effective way: https://www.hometalk.com/diy/outdoor/pest-repeller/ants-safe-and-effective-cure-36651130

Ants: Safe and Effective Cure

Hi Julia. Here's an all natural ant spray: Mix together: 2 cups Vinegar, 2 cups water, 3 Tablespoons Blue Dawn dish soap, and 3 Tablespoons table Salt. Mix until salt has dissolved. This is safe to use around kids and pets.

Hi Julia

Try white vinegar and water.

Ants really hate vinegar, and you can make a cheap, easy pesticide just using vinegar and water. Mix a 50/50 solution of vinegar and water in a spray bottle. Spray it directly onto the ants to kill them, then wipe up the ants using a damp paper towel and discard them.

Cinnamon keeps ants away - sprinkle straight cinnamon at base of plants after using hose to spray majority off the plants. Ants won't cross the line to get back onto the basil. Don't use vinegar - it will kill the basil.