That is very odd. I've never seen more than 1 or 2 of them together before.
The other night, my family and I were on our back deck around Midnight talking (with a big outdoor light on) and a Mockingbird was singing his album. We decided to have fun with it - and we whistled back different notes. He copied almost every one - right after we would whistle them. It was pretty cool!
I am beginning to believe they really like people!
Sharon Calahan