The crebiks hang from the tree limbs of the forest, waiting for their prey to appear. The crebiks use their weight and armored shells as their weapon, releasing their grip when the prey comes into position directly below them. They fall like a hammer onto their prey, hopefully killing it and breaking open the thick shell. However, if this falling attack does not kill the prey, then the crebik will use its mandibles and pincers to finish it off.

The armor of the crebik itself is so thick and strong that none of the other large predators of Troos can kill them without a determined effort. Instead, the crebiks are preyed on by extremely tiny insects. Every time a crebik drops from its perch, it runs the risk of cracking its shell. When the shell becomes cracked, tiny insects known as bahl flies crawl through the cracks and begin to eat the soft inner flesh of the crebik. Because the bahl flies are so small compared to the crebik, an infestation may last for several weeks before it kills the crebik.

Once every Troosian year, there is a great migration, and all the crebiks in an area will travel to the nearest large body of water. At the end of the migration, the crebiks enter the water and begin to drink. The water that they consume fills bladders just beneath the armor plates, causing the armor to expand and expose the soft flesh underneath. In this vulnerable state, and in the relative safety of the water, the crebiks begin their mating dance. At the end of the dance, the crebiks drain the water that they have consumed and return to the forests. Half a local year later, a large number of juvenile crebiks are born.

Crebiks do not develop their armored shell until after the first year of life, so the juvenile crebiks are easy prey both for members of the other species and for adult crebiks.