I've noticed that many people put up small animals for adoption for free on craigslist and was wondering if those animals are occasionally used as feeders or if using a persons pet as a prey animal (prekilled) is a taboo subject? Recently I've noticed several ads for mice and rats for free and feel like many of them are likely used as feeder animals. For those species it makes sense to me, but what about other rodents such as hamsters, guinea pigs, and rabbits? I could see them being viewed the same, as they are similar to rats and mice nutritionally and reasonable meals.
Does the same idea translate to animals that our culture views as solely companion animals though? For large monitors and constrictor snakes something like a ferret, bird, or small cat or dog wouldn't be unheard of as a natural prey item. I can see how they would be an appealing source of free feeders, but what about the ethics of feeding someone else's pet to your own? Are people who put up their animals for free adoptions taking an unknown risk that their pet may become a snack for a large reptile?
I am in no way saying that I support adopting companion animals with the intention of killing and using them as prey items, I'm just looking for information from the community.