James and his contractor prepare a batch of ANFO (ammonium nitrate + fuel oil) to blow up the mound. This is a 'tertiary' explosive, which means you cannot set it off with fire. It would just burn. To set off the detonation, you need to explode a secondary explosive, like a stick of dynamite, which in turn needs to be set off with a primary explosive, like a blasting cap.
When James is driving back from the old man's house, he tries to call home but gets no answer. The sound effect you hear is one of a phone off hook, not a busy signal.
Any responsible teacher would not give kids ant farms with a queen, since queens can live for years, producing ants for 1-20 years. Ant farms are not designed to house a queen ant and the thousand of young she produces.
Shooting a double barrel shot gun three time without reloading, and he only had two shells to start with.