Besides proving that postage was paid, stamps also used to function as legal tender, at least where I live. I remember posting stamps as payments of small amounts instead of writing a tiny cheque or requesting bank details.That’s not the case any more. Even the post office can reject to buy back of stamps now, so they don’t function that way anymore.
Yes, sure it can. Mashed/blended spaghetti bolognese or lasagna are available as baby food.
Baby food products are basically just ordinary food blended and packed in smaller convenient portions. Simply look at the package to see what it contains.
Cat and dog foods are completely different kinds of food, which is often made from animal biproducts and not suitable for human consumption.