Tonight our cat returned home with a live mouse in its mouth.  It dropped
the mouse at our feet, whereupon the mouse ran, and then it picked the
mouse up again.  We picked up the cat and placed it back outside, not
wanting the mouse running around inside.

Since then, the cat is acting different.  He went back out and when he
returned, rather than meow to be let in and run in when the door was opened
as always, he simply sat there, and I had to convince him to come in.  Now
that he's in, he's really quiet, and also a little more jumpy than usual.

Out of curiosity, do you think our cat is upset at our not accepting its
gift?  I'm quite curious about cat behaviour, so I had to ask.  :)