Creeps are your units. Creeps can move, harvest energy, construct structures, attack another creeps, and perform other actions.
https://docs.screeps.com/api/#Creep
Tick at which this creep will expire
Optional
Temporary effects that are active on this object
ID of the user who owns this object.
Note: NPCs do not have long-form hex ID strings like normal players:
Creeps are your units. Creeps can move, harvest energy, construct structures, attack another creeps, and perform other actions.
https://docs.screeps.com/api/#Creep