My Neighbor's Dog Ate My Cat

Now I'm feeding her 3 two week old kittens. And I'm learning waaaay more about
cats than I ever wanted to. Like for instance, I don't think grooming is just
grooming. I think it's a necessary act - as necessary as eating (for their
nervous system??)! I have to simulate grooming with a warm damp washcloth.

But I'm confused about two of their behaviors. It's their "nose" activity. The
kittens seem to enjoy pushing their noses into my hands or arms or whatever.
And they like to stick their heads through holes. If I hold my finger and
thumb together to form a hole - they'll stick their head through it everytime.

What are they doing that for?

And if there are any inventors in here, please consider developing a "Mama
Cat." Basically, it's just a soft furry stuffed animal that randomly purrs and
has about 12 nipples sticking out of its belly. Preferrably, the nipples
should be attached to a removable bottle that people can fill with milk! Maybe
the "Mama Cat" can be plugged into a wall to generate heat too.

(Or is this already available?)

sigh