Just started today I think. Didn't notice them yesterday. Ants are black and medium sized, flys look like regular house flys. Just on two lily stalks (no flower on anymore), and a couple african marigolds. Any ideas? I'm a new gardener. Thanx, all! Tyler

There may be scale insect on the plants. It's like a tiny little dome shaped pest which exudes a sweet honeydew. The ants and flies are attracted to the sweetness. Have a close look. If that is the case, A spray with whiteoil will take care of them.
To make your own whiteoil, take 1 cup cooking oil, 1 1/2 cups water and a teaspoon of washing up liquid. Blend. Dilute 10:1 to spray. Don't spray on a hot day.

Thanx Longey, going to try it today. Tyler