My cats had been fine eating their nutro indoor kitten kibble, but then they started to just pick at it instead of eat it. So then I bought some innova evo and started mixing it in (that is some smelly kibble) and one of my cats is all over it. The other cat doesn't seem to like anything, but kit n kaboodle or meow mix (unfortunately, he's not allowed to eat that stuff anymore). Do cats like to switch up their dry food? Should I be switching it every now and then? I give them plenty of variety in wet food but they hate it all.