The first time around I just cut the whole bird up in half (yuk) and woohoo! A 'wild' reaction from the kittens: the two boys batted their bits around the kitchen for half an hour before eating them - huge fun to watch but I spent another hour cleaning blood from the floor and walls.
Next time I tried pulling some of the feathers off with my fingers (they come off easily enough) and that seems to have calmed the situation - no more batting just munching (Miki even ate two halves in one sitting, and wanted more - maybe I should stop cutting them up?). Several quail meals later they are still really happy with it - every last bit gets munched up enthusiastically, feet, heads, beaks and all.
I tried mice too - not as huge a hit: the kittens will eat them happily, but Psipsina will not go near a mouse, not even a cut up one. Strange (but I obey and offer something else). Just like the feathers the fur seems to provoke real predator behaviour - the mice get batted around for ages before anybody will start eating. At least the mice are whole so no blood to wash off the walls!