At dusk I noticed through the window a rabbit in the back garden. As I was asking my daughter to go chase it away, she says, "what's THAT?!" and I see a black squirrel-like animal dart across our composter and climb up our giant pine tree. It was fast, a bit longer than an Eastern squirrel but sleek. I looked at pictures online and maybe a Fisher cat is the closest. What options fit this description in the Northwest suburban Chicago area?