Yup, here in FL we do have to 'share the harvest' with all kinds of critters. I have an ongoing battle for 2 months in the summer while my mangoes are ripening. Squirrels really love them, and they will drop one to the ground by chewing through the stem, eat about a teaspoon of the fruit, then leave it to rot. When they come back they don't go back to the one on the ground, they choose a new one. Friends with an avocado tree say that the raccoons love their avocadoes, and that the 'coons are so fat by the time the avocado is finished bearing their bellies drag on the ground.
Btw, it does take probably 7 or 8 years to grow an avocado tree from seed to bearing size. Then (as with many fruits grown from seed) what you get won't likely be the same as the fruit that the seed came from. Same with citrus of any kind, it's at least 5 years to your first fruit (you should remove any fruit that forms on small trees) and they most likely will be what is known as "sour orange" which is the rootstock that most citrus trees are grafted on. Not awfully tasty.
I do plant seeds from things like peppers, though. Again, you never know what you're going to get but at least it's not "sour orange".
