The formation of casein involves the curdling of milk.
She dropped back to her pillow and yawned The sound caught her by surprise - a blood-curdling scream that could be nothing less than a woman in agonizing pain.
Coyotes are creatures of slinking and stealthy habits, living in burrows in the plains, and hunting in packs at night, when they utter yapping cries and blood-curdling yells as they gallop. Hares ("jack-rabbits"), chipmunks or ground-squirrels, and mice form a large portion of their food; but coyotes also kill the fawns of deer and prongbuck, as well as sage-hens and other kinds of game-birds.
A scream—not the blood-curdling variety, more a high-pitched screech—from upstairs broke his reverie.