O script de tiro do filme é extremamente claro que as maiores criaturas (mais tarde identificadas como bio- repositors no comentário) são os adultos, as criaturas intermediárias são adolescentes e as criaturas mais pequenas são meros filhotes. Eles são todos da mesma espécie e, sim, são alegremente canibais
A NOISE from the supply room. Is it Ali? Just too scared to come out? Imam opens the door... And hatchlings pour out.
Moving with a gang-intelligence, they circle the room in a wave, soar high into the rafters -- then plunge into the coring shaft, SQUEALS VANISHING to infinity. Shocked silence, then...
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RIDDICK'S POV: In degraded image, we see the predators -- adult hatchlings -- emerge from the spires. They're large, mammalian, hammer-headed. They CLICK with echo-location, sounding out the world they haven't inhabited in 60 years.
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RIDDICK'S POV: Of an adolescent predator. It squats atop cargo, eating a hatchling. A heavy bone-blade crowns its skull.