Graboid - Behavior

Behavior

Graboids are shown to be ravenous carnivores, always on the hunt for food. Indiscriminate eaters, their diet includes sheep, cattle, horses, donkeys, coyotes, and humans. They are known to be cannibalistic when the opportunity presents itself; El Blanco consumed an ass-blaster in Tremors 3. Lacking eyes or a nose, they are shown to hunt by sensing seismic vibrations which are produced by sounds and movements (such as walking). Because they are unable to tell the difference between edible and inedible vibration sources they adopt a policy of "eat first, ask questions later", swallowing whatever sets off their vibration sensors and regurgitating anything that is inedible. Inedible objects can be spat out with considerable force, being propelled high into the air. Due to the sensitive hearing they use for underground navigation, graboids are so sensitive to sound they must retreat from loud explosions, which cause them great pain.

Graboids are ambush predators, preferring to sneak up on their quarry, though they are shown to chase it down with great determination. They erupt from the ground and use their tentacles to ensnare prey, pulling them into their mouth (sometimes only the tentacles break the surface). The tentacles wrap around the prey, biting into its flesh or hooking the prey with their horn-like spikes. When prey attempts to flee by climbing (for instance onto the roof of a house or car), graboids will dig away the earth under the hiding place, undermining it until it collapses or sinks low enough to allow the graboid to pluck off the prey. When they are unable to break down the prey's hiding spot, the undaunted graboids will continue circling it, like sharks at sea, until it ceases making vibrations. Usually they wait so long the prey dies of dehydration or starvation, i.e. several days.

Graboids are depicted as highly intelligent, possessing memory and the ability to learn. For instance, in the first Tremors movie the characters successfully killed a graboid by having it swallow homemade dynamite. The second graboid (nicknamed "Stumpy" by Val) had apparently noticed this trap and simply regurgitated the dynamite. Other examples are when the characters escaped on a bulldozer which was too big to be toppled (weighing 30 tons) or undermined (it could drive away before the graboids had a chance to dig away enough of the dirt under it), the creatures dug a trap in its path.