Tick (Doom 3)

The tick is a small, spider-like enemy in Doom 3 that has similar attack patterns to the trite. They appear only once in the Delta Complex, but they come in giant swarms. An example of this is found when the player reaches a weapons cache in Delta Labs just before that in which he fights two Hell knights for the first time. In Doom 3: Resurrection of Evil, ticks are encountered several times throughout the game, their last appearance in Hell. Notably, they make no appearances in The Lost Mission at all.

The only noteworthy differences between ticks and trites are aesthetic ones (although the tick can jump slightly farther than the trite). While trites resemble an inverted lost soul with legs, ticks appear more insect-like. What's more, while the trite makes a deep, throaty roar, the tick makes high-pitched chirps. Finally, while trites curl up and burst into yellowish-green "spider juice" upon death, tick corpses burn away like all other demons. If closely examined, a little human face can be seen on its head.

Tactical analysis
The tick cannot attack while the player is on a significantly higher vertical plane. For example, if a tick is on the floor, it can be rendered harmless by jumping onto a bunk bed.