"Yeah but the issue isn't really that they're selling without informing people, it's that they're selling at the expense of the animals. If they kept the bettas healthy (and in nicer containers/actual fish tanks) I would have no qualms about buying from them. "
But this is true with all their animals - none of them are in ideal conditions. The babies aren't in any worse conditions than the adults, and so far at my store I've not seen any dead in their cups. Mine was just a tiny thing when I got her - less than half an inch long, totally transparent and very stripey. But she readily ate finely crushed flake, Hikari betta bites, and micro pellets as well as finely chopped bloodworms and brine shrimp. Petco's goal is to make money so they are not gonna purposely starve and kill their merchandise.