There are no specialty kitten mice in the wild, and some dry foods like Wellness Chicken Kitten and Wellness Chicken Adult are for all intents and purposes identical (same fat/protein/mag/ash/etc and 99.9% identical ingredients list).
Kittens simply require more calories and higher protein/fat percentages of their diet to maximize their growth, and many indoor adult diets don't offer that especially the lower tier brands.
Wilderness on the other hand does, so I would consider it a "all life stages" food. I am feeding their dry formula to mine, and they seem to really like it. For wet, we were doing Wellness chicken until they got bored with it, now we do a bit of everything as long as its rich and has quality ingredients.
