Petco and Petsmart ball pythons come from "Captive-Hatched" shipments. Basically, over in Ghana, Africa every year gravid females are collected from the wild and kept on "farms" until they lay their eggs. The eggs are removed and incubated in communal pits until they hatch. The females are then either returned back to the wild, or, slaughtered and sold for canning (ball python meat is popular in Asian countries). As soon as the eggs hatch, they are put in crates (by the thousand) and flown to the U.S. and other parts of the world for sale in the pet trade.
Generally, mites aren't a problem in captive hatched shipments because reptile mites are actually native to southeast Asia and so long as ball python shipments from Africa aren't mixed with shipments from other parts of the world - there's no exposure to them. Can't say the same about ticks, but ticks are much less prolific and a lot easier to get rid of than mites. Most of the time, imported ball pythons catch mites at the wholesale facility AFTER they arrive in the states. Wholesalers mix shipments from all over the world and this is often where parasites are introduced to them.
I've had the opportunity to see ball pythons shipments being opened by importers here and it looks like they do a pretty good job packing them and making sure that they survive. I was surprised at how clean they were. I didn't see any dead-on-arrival. The ball pythons arrive dehydrated and unfed - intentionally - to keep defecation to a minimum which during shipments, could cause a problem when you are talking about thousands of snakes bagged in one large crate. In the days prior to hatching, ball pythons absorb the yolk of the egg, a first meal so to speak before hatching, which sustains them for their first few weeks of life. Upon arrival in the states, baby balls are soaked, rehydrated, and usually have their first shed immediately after. They then find their way to various pet stores or reptile shows for sale to you and me.
I've kept a few captive hatched snakes in my collection. It is hit or miss. The ones I have kept have been more "jumpy" than captive bred and born snakes.
