They don't "kick" but I do understand what you're talking about. I have an 11x9x9cm fibroid and I feel the "kicking" you're talking about. It was explained to me that I'm feeling a kink in the blood supply leading TO the fibroid. The next time you feel it, concentrate on your heart beat. You'll notice it matches up. Shifting position will cause the "kick" to stop.
And yes, to the person who replied "fibroids aren't alive", they *are* alive. They aren't sentient.
And yes, to the person who replied "fibroids aren't alive", they *are* alive. They aren't sentient.