Why do I have a blinking Bluetooth icon?

After months of using my MacBook Pro, it has developed an annoying tic. The icon next to the blue "Search" icon at the top right of my screen is blinking. It goes from a black diamond against the white bar, to a black battery with a different icon on it. However, I'm not getting the usual notice that the batteries are low in my Apple wireless mouse or keyboard. When I position the mouse over it, I get a Bluetooth menu that shows both my wireless devices, says Bluetooth is turned on, and gives me some other choices--none of which seem to need any attention.

Does anybody know why this annoying blinking has started and how I can turn it off? Thanks, Chris