Salad on the side?

Our twelve-year-old female cat is a dedicated consumer of rodents ... what she catches, she eats. In order to keep the mess inside the house at a minimum, we watch closely whenever we let her come into the house, so that she will have her rodent meal outdoors. However, in the summer, when we anticipate being away for a day or more, we leave a window open so she has access to her food bowl and water. This also enables her to devour her catch inside. No surprise there. We know that she has enjoyed a meal because she does not eat one internal organ and -- finally I get to my point -- she leaves near that organ a few blades of grass or leaves. I think this is new behavior, but am not certain. I assume that she must bring the vegetation inside after she has eaten her prey.

My question: have any of you observed similar behavior and can you explain it?

Perhaps her aim is getting worse in her older age and she`s bringing in the grass with the kill, or in her toes?

Our mouser (well shrew-er), Miss Kitty, also chooses not to consume the stomach because of the acid. Thats how we know Tasha caught a mouse (that she so kindly left in our bedroom for me to step on in the middle of the night)... she took one big bite of the stomach and promptly threw up everywhere and didn`t eat the rest of her catch .