What is that? I've never heard that before... could it be a rattle snake???

I couldn't find it... Luckily a cat came by and he stared at the snake and then I found it in the corner of the backyard.  Sure enough it was a rattlesnake.  And it knew I was there and it knew cats were around them.

Here are some pictures of this snake.

He's all curled up in the shade.

Is he trying to get out of the backyard?

He's extended now... he's pretty long.