As for eggs, Chickens will actively eat their own eggs. Yes, wild ones will lay for the sole purpose of egg, not just procreation. Same thing goes for milk, if resources are very low, some mammals will drink their own milk, yes, straight from their own tit.

These are designed by default to be food. If you do not eat them, their owners WILL eat them.

Plants are the actual brain/stems of the plant itself. You are literally eating a giant open pain nerve. Fruits, most, are flowers post bloom designed to carry the seed in a tasty format so an animal can transport them vast distances. They literally evolve to be eaten.

Make sure to spit out the seeds... also, pineapples are not true fruits, but rather the bark of the tree itself. Therefore, off the pizza and off the menu.

Plants do have a structure akin to a brain. Guess what doesn't, jellyfish, they don't even have a heart. Meanwhile, bugs have both and vegans will say it completely justified in eating them. Yet they won't each jellyfish.