I spoke to my main post office in a city with a metro population of 600,000. I had a few moments to ask them some questions about shipping packages. I asked them about the treatment of normal packages, versus fragile. They told me normal packages are tossed, and not much care is given to them. Fragile packages they handle more gently, try to put them on the shelves where chance of damage is lessoned. I then asked about hatching eggs. At that point they said they handle them with even more care, doing everything to make sure they are not damaged. They recommend that you mark the box on all sides in a bright color to attract attention.