Ants on your plants can be upsetting, but they do no harm--directly. However, ants are industrious farmers that collect other insects, such as destructive aphids, and bring them to plants those insects like to eat. The "cows" then excrete a sticky substance known as honeydew, which the ants eat. But ants can pose problems if they get into stored grains, pet food and other items that you'd rather keep to yourself. You can use poisonous baits or more natural remedies to keep ants at bay.
Prevent ants from swarming to your yard by keeping it clean. Make sure your garbage cans are tightly covered, keep pet foods in sealed containers and clean up any food messes as soon as they occur.
Make an insecticidal soap spray by mixing 1 tbsp. of non-ultra dish soap with 1 qt. water. Put it in a spray bottle and then spray ants and their trails every day or two until you see far fewer insects.
Spread a layer of organic diatomaceous earth around plants on which you have noticed ants--it cuts their feet so they don't walk over it to get to your plant. Reapply this material after it rains or after you water the area.
Combine 1 tsp. of boric acid with ½ cup apple-mint jelly, which makes an effective ant bait because the jelly attracts them and the boric acid kills them. Drop globs of this mixture every 1 or 2 feet along noticeable ant trails and repeat when you see the globs disappearing.
Mulch with cornmeal and/or cedar chips around affected plants. Ants will eat corn meal and then swell up when they drink water. The cedar chips act as a natural repellent against ants and other insects.
Pour boiling, soapy water down ant nests at night wherever you find them. Repeat every night for three nights.