ORBS in the house?

The other night, in our bedroom, the wife and I were scared half to death because these strange lights suddenly appeared in the darkness.

They were moving very fast and changing color from red to blue to yellow and back to white. They were very bright and moving in all directions. They left a trail of color as they moved, a bit like a comet but when they stopped they were perfectly round. They were about the size of a tennis ball.

They flew around for a while then vanished as quickly as they came. I couldn't get back to sleep that night. I was very interested to know what they might be so I looked on the net and discovered that they might be orbs.

The next day my daughter came round with the grand kids and I wanted to take a photo of my youngest so I snapped away and captured a strange ball, much like the ones in the bed room, with my digital camera. Hope you can tell me what it is because we have seen quite a few since.