If you are tired of ants crawling on your picnic table then place the legs of the table into 4 sturdy pans or bowls of water, the ants will not be able to cross the water to climb up the table legs!.
Other tips are:
Wash the top of your table off with vinegar, ants hate vinegar. You can also put some pet food in bowls that surround the table legs, ant won't cross over this either.
Sprinkle salt around the area where you will be eating. Ants won't cross over the salt trails that you put in the grass.
