A testament to the control the Horde has over it's creatures, tickers are fast, small creatures strapped with explosives that detonate on death. They are common in ambushes since in the hectic combat, it can be hard to notice them scurrying around. They are also particularly dangerous to fortifications in games like Overrun where they can dash up to a fortification and deal damage to the target until either it is taken down or killed. The hope is that if you can do even a small amount of damage, even being killed will result in the destruction of the fortification.
While it may seem appropriate to rush the enemy becaue of their size and speed, their lack of endurance means that it's much better to take it slow up until you actually attack. During this time, you can get up close, bypass wires, or even be punted up to a lookout point for a surprise attack.
