Feline Mystery - Solved!

Nick and Nora Charles - the intrepid solvers of mysteries - have solved my feline mystery. To summarise, my cat Nimrod went through a phase of presenting me with headless mice, and later presenting me with the mice heads marinaded in a vomit sauce. This was less endearing than might be supposed, and contrasted sharply with her utter refusal to eat Mr. Whiskers Finest Rabbit and Beef chunks. The Charles' hypothesis is that:

"Puss is probably not eating the mouseheads for herself but as part of preparing a delicacy to deliver to you in return for your provision of food she likes. Chewing off the head is simply getting rid of the only bit of a (living) mouse that can do any harm - to her at least."

which I must say sounds very plausible. Further evidence to support it lies in her new habit of biting the heads off without eating them. This is a much preferable state of affairs, although now trails of blood festoon the living room carpet, so swings and roundabouts...

Cats rule.