The Harvester is slow and heavily armored (with the same armour and health statistics as the Mammoth tank of the same era). Because of its heavy armor it is difficult to destroy with small arms, meaning that attempting to destroy one without heavy weapons (such as a Rocket Launcher), tanks, or air support (ORCA) would take a long time and waste valuable ammunition. Its vital role meant it is given heavy armor but because it was not intended for front line combat or to come under prolonged enemy fire it was not given any armament to defend itself. Although it could run down infantry, it was typically piloted by a civilian driver who followed a preset route (focusing on collecting the TIberium and returning to base as soon as possible) and therefore it could be avoided rather easily.
Explosive weapons are recommended to destroy the vehicle. However care must be taken if attempting to do so on foot, not only due to the risk of being run over, but if using C4 (Timed or Remote) the need to get close would be apparent, as it operates primarily in Tiberium Fields the risk of poisoning is high. Thus it is suggested to engage it at long range or to use close ranged explosives when it is traveling to or from the field.
The Harvester is also capable of self-repairing, in a similar manner to the Mammoth tank.