HERES MY THEORY MY CATS DO THAT WHEN EITHER THEIR CAT FOOD IS OLD LIKE WE BUY BIG BAGS AND WHEN IT GETS TO THE BOTTOM THEY HATE THAT AND REFUSE TO EAT IT OR THEY WANT YOU TO SWITCH TO ANOTHER FOOD BC THEY ARE TIRED OF THAT THATS WHAT MY KITTIES DO AND YES MINE ARE PIGS TOO