Additionally, props were manipulated on the live set in anticipation of how the jumbo spiders would ultimately move through each scene, bumping into and smashing things, to create the complete and realistic final effect.
Says Scott Terra, "sometimes they used a taped X, a tennis ball or a spider model as stand-ins to indicate where they would be, more as a marker for the camera than the actors. It’s not easy to act scared when you’re looking at a tennis ball."
Enhancing the general creepiness of the visuals are the film’s spine-tingling sound effects, overseen by Scott Wolf, MPSE. It was his job to imagine what extra-large arachnids tearing up a small town would sound like, which he does, from the snap of their incisors clamping down on their prey to the ominous swish of saliva in their giant mouths. And anyone who has ever winced at the sound of a gentle crunch when squashing a spider on their bedroom wall will appreciate the resounding crack made when these mutants get their gargantuan legs shattered in battle.
In addition to computer imagery, Creature Effects supervisor Bill Johnson provided numerous mechanical models of the super-sized spiders and was responsible for creating the sarcophagus-like silken cocoons that contained the orb weavers’ human victims.
Of course, there were also plenty of live arachnids on hand once filming began. Arizona’s Pets Inc., a facility that raises and sells hundreds of varieties of spiders to collectors, provided some 200 individual creepy crawlers to the production, including a Goliath Bird-Eater tarantula, for scenes filmed prior to the spiders’ toxic enhancement. Pets, Inc. owner Don Hayes and manager Bill Ingles confirm that the Goliath is the largest tarantula on the planet, adding that there are "over 2,000 known varieties of tarantulas alone, only four of which are considered dangerous. The majority are docile and harmless."