I wonder how the guy keeps baby from eating the other two snakes in its same habitat.... can't snakes be aggressive? or they don't care about other snakes until they are hungry?
Yes they can, but bare in mind they are for a reason, be it hunger, or male combat in season, etc. Snakes can be kept together, but I dont ever recommend mixing species or housing 2 males, nor ever feeding snakes together or housing snakes of significantly different size (unless its a pair, even then). Any of those is recipe for disaster.
Its likely he kept them overfed.
They will bite and lacerate the crap out of one another in some cases, sometimes to the death without intervention. (cant escape each other in captivity) (not all get nasty but its normal when males combat for a female) Mostly little damage is inflicted, atleast in the wild. . Intrestingly, some venomous snakes are quite gentlemanly about it and inflict no damage at all, rather having a graceful and amusing wresting match, in which each tries to push the other to the ground.
It can last hours and eventually one conceeds and simply wanders off, neither wasting a single drop of venom and without a single bite. (youtube/google King cobra male combat)
Feeding together: Theres no actuall biting/fighting but boths instincts will kick in and both will try to eat the same food source, aka each end of a rat. One will keep going when the rat runs out and eat the other (or try) usually leading to the death of both.
Fighting over territory (in captivity) is pretty much unheard of, the larger simply dominates, getting the best hide, basking place etc. The dominated one lives in stress and its immunity to disease will weaken, it becomes ill and stops feeding etc.
large constrictors are not known for eating other snakes.
Generally no, since 'large' snakes require/utilise large food sources which normally is mammals,
however constrictors all start on small ectothermic animals like lizards frogs and yes, small snakes if opportunity arose, before moving on to more substantial mammalian prey as they grow. Some constrictors are cannibles and are geared to munching others, like black heads Aspidites melanocephalus and womas. Both these eat smaller snakes aswell .
Black headed Pythons predominately feed on reptiles including other snakes but will eat mammals.
heres a vid of ball python males combating
http://www.youtube.com/watch?v=a7A0LhtKJAY
carpets
http://www.youtube.com/watch?v=ACsvNd7vwa0