A oval-like object with pinched sides surrounded by an effect similar to a heat shimmer that bent and colored the light around it.

My mother was in the backyard, watching the dogs, and noticed a heat shimmer in the sky out of the corner of her eye. She turned and looked at the object. She sat and watched it for 10 minutes as the object darted around the sky in an erratic manner.
Then, at 1:17pm, she came into the house to get me. I went outside with her and spotted the object. At this point 3 more similar objects began to appear, as if they simply faded into existence. Two objects remained where we initially saw them, and two others—including the original object—moved across the roof of the house.
The original object and one of its companions then hovered above the treeline near our house. The original object darted around erratically at extremely high speed. Then it's companion merged with it. Afterwards both objects became stable.
During this time the objects were surrounded by a glowing light shaped like an oval. This light 'smeared'—for lack of a better term—the objects shape. We could not see any physical object inside the heat shimmer. No metal, no craft, only the shimmer. The objects glowed brightly, changing colors from blue to pink to green then back again. It mainly remained pink.
The objects stayed stable and floated in air while my mother went to get a camera. As soon as she exited the house, the two objects rocketed away with instant acceleration from hovering.