I have used the African Soft furs before, more as a trial than anything. I don't find them anything special really....well they are rather cute, rather acrobatic at times and are not difficult to hand tame. They grow a little bigger than mice but not big enough in my view, to make them a good feeder rodent for ball pythons, at least not in the long run. Doesn't help that ball pythons will imprint on these things.
The biggest appeal of these rodents is their low levels of odor. They don't stink as fast as rats nor have the musk male mice urine has. They poop just as much as mice if not more and thrive well enough on regular mice/rat lab chow. Their gestation period is the same as mice and the litters are a little larger..but not really that much.
The drawbacks...they are big chewers and jumpers. If not tamed up a bit they can be real biters. (the ones I bought were handed tamed and no where near as skittish as mice). They also do best in small groups..one male to 2 females. Larger groups and they tend to cannibalize and fight.
I have fed a few to my corn snakes but didn't get any different reaction feeding wise than I would with mice or rats. My corns have always been great eaters and will eat anything and everything I offer...except during shed.
Personally I think these guys are more a 'fad' than any real break through feeder. They can be a fine alternative or used as variety...or helpful with really stubborn feeders. They are not very hard to get, though you may have to check reptile shows and classifies to find a local breeder, if you want live ASF's to breed yourself.
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PHLdyPayne