Between the trees the air seemed scarcely to move. The heat had thickened it, so that the winged insects sat torpid on the very leaves beneath which crouched the mantis and spider, too drowsy to strike. Along the foot of a tilted, red rock a porcupine came nosing and grubbing. It broke open a tiny shelter of sticks and some meagre, round-eared little creature, all eyes and bony limbs, fled across the stones. The porcupine, ignoring it, was about to devour the beetles scurrying among the sucks when suddenly it paused, raised its head and listened.
It is again a quotation from Shardik by Richard Adams. Only possible definition of suck seemed to fit the situation I found is an act or instance of sucking; or sound produced by sucking. But how the beetles can scurrying among the sucks if the porcupine was just about to devour them. Though right now I think this is also nonsense: the porcupine doesn't suck at least to devour something. And I just thought it also can be an epithet to some object mentioned before (but if it is then I can't recognize which one), for this case I put as much context as possible. So I'm really confused about the meaning of the sucks here.