Factual error: The crew gasses out the ant hill by dropping chemical grenades into the hole. But there are two reality mistakes about the grenades: 1) chemical grenades do not explode; they spray their contents into the area; and 2) considering the size of the ants, the size of their nest must be gigantic, and therefore, it would take more than a hundred grenades to flood it completely with cyanide gas.
Trivia: When Ben Peterson is killed by a giant ant, he emits a high-pitched, half-choked death scream. This scream has been used in many other movies ever since: in Small Soldiers (when Brick Bazooka loses his legs); in Star Wars - A New Hope, when Luke shoots a stormtrooper in the shaft-swinging scene; in Lord Of The Rings - The Two Towers, when an Elf warrior is thrown off the Helm's Deep wall; and in Lord Of The Rings - Return of The King, when a Gondor soldier fleeing from Osgilliath is snatched up and dumped by a Nazgul steed. I guess that makes it the most used death scream in movie history.