Mine loves Versele Laga Nutties, and I like them because they are a natural treat. They are ridiculously expensive (about 2 or 3 euros) if you think about how much the ingredients would cost separately, but let's face it, buying the Nutties is easier.
I'm going to show some photos that aren't mine (credit to mylittlemonsters.pl)
(I don't know why on the last photo the rice pops aren't shown, and on my bag I also found whole pumpkin seeds and another circular pellets that aren't shown on the picture)
Versele laga has other natural snack varieties (fruities, veggies and cereals that i know of) but I don't know how they are (and if they are natural as they stated) as I've never bought them