Sleep
Sleep is a basic need for 
beavers. Unlike some other basic needs like hunger and thirst, leaving sleep unfulfilled will not result in the death of the affected beaver. Instead, it just results in reduced beaver movement speed.
Requirement
A space for the beaver to sleep. A 
house or an empty tile will suffice.
Satisfying Need
Beavers will only sleep during the final hours of the day. They will not go to sleep sooner than is required for them to be fully rested for the start of the next day, even if they are exhausted.
Beavers will not sleep while employed during work hours or while they are finishing up a job. This means that any beavers that are doing a time consuming activity (such as hauling resources a large distance away) may end up working later into the night. If the work hours are set too high, beavers may not be able to finish their job by the time the next day starts, in which case they will forgo sleep until they become exhausted.
Whenever a beaver goes to sleep, they will rest until their sleep is nearly full.
Exhaustion
When a beaver is exhausted, they will immediately head home to sleep or, if they don't have a home, they will find a nearby tile (preferably empty) to sleep on. When a beaver is exhausted, their next sleep will only be 66% as efficient (requiring them to sleep 1.5x longer than normal). Under some conditions, a housed beaver may pass out on the tile they are standing on instead of going home (causing them to sleep even less efficiently than normal) - this might happen for beavers who take a while to finish a particularly long job (such as planting or hauling something).
Rate of Change
Beavers lose 60% of their sleep need every day. Sleeping restores a varying amount per hour:
| Location | Exhausted? | Restored/h | Average sleep needed |
|---|---|---|---|
| Lodge | No | 20% | 2.7h/day |
| Lodge | Yes | 13.2% | 3.8h/day (7.6h per session) |
| Outside | No | 15% | 3.4h/day |
| Outside | Yes | 9.9% | 4.8h/day (10.1h per session) |