Many pests are hardly or not at all seen during the day. They stay hidden, move only in dark areas, and only become active when it is quiet. That is exactly why an infestation is often noticed late.
But what do these animals actually do at night – and why are so many species nocturnal?
This article shows which pests are active at night, why they come out then, and what really happens at night in the house, hotel, warehouse, or business.
Why are so many pests nocturnal?
1. Protection from enemies
There are fewer natural enemies out at night.
Many pests have evolved:
- Mice & rats
- Silverfish
- Cockroaches
- Moths
- Spiders
They use the quiet to search for food without being seen.
2. Darkness means safety
Many pests are light-shy.
Light means:
- Danger
- Human activity
- less cover
Dark rooms offer them protection and orientation.
3. Less movement inside the building
At night: no footsteps, no doors, no disturbances.
This is the ideal moment to:
- to search for food
- to find new hiding places
- to explore pathways
- to collect nesting material
4. Temperature & humidity change
Humidity often rises at night – especially in:
- Bathrooms
- Cellars
- Kitchens
- Storage rooms
Silverfish, spiders, and woodlice become especially active as a result.
Which pests become active at night?
Cockroaches
They are typical night hunters.
At night:
- they leave their hiding places
- search for food & water
- explore new areas
They are a strong hygiene signal.
Mice & rats
Rodents are crepuscular and nocturnal.
At night:
- they use fixed pathways along the walls
- gnaw on cables, food, or packaging
- collect nesting material
They are often heard in walls or cavities.
Silverfish & paperfish
They rarely come out during the day.
In darkness:
- they search for moisture sources
- roam bathrooms & kitchens
- feed on organic residues
They are an indication of moisture.
Moths
At night they fly towards light sources.
In kitchens & storage rooms:
- larvae become active
- hidden cocoons open
- new infestation sites develop
Spiders
Spiders use the night to:
- to build new webs
- to catch prey
- to wander between rooms
Especially common in cellars & attics.
Woodlice, springtails & cellar beetles
They come out at night from damp areas:
- from drains
- behind washing machines
- from cellar cracks
Hardly visible during the day, often numerous at night.
What really happens at night – a look behind the scenes
1. Pests use empty rooms
Whether kitchen, hallway, or workshop – rooms are free at night.
Pests use the time to:
- to rummage through supplies
- to visit garbage areas
- to try out new routes
- to eat undisturbed
2. Pathways are "learned"
Nocturnal pests repeat the same routes every evening.
These paths later reveal:
- Cause
- Hiding place
- Infestation site
(e.g., grease marks from rats or droppings from mice).
3. Spreading mostly takes place at night
Pests:
- create paths between rooms
- penetrate new areas
- find new nests
- transfer from box to box (logistics!)
4. Monitoring is therefore especially important at night
Traps, glue monitors, and electronic systems record at night:
- Activity
- Type
- Intensity
They provide the data that remains invisible during the day.
✔️ Conclusion
More happens at night than you think.
Many pests stay hidden during the day and only become active when it is quiet.
Darkness, humidity, temperature changes, and lack of disturbances make the night the ideal time for foraging and spreading.
Those who understand what really happens in the building at night can detect pests faster and intervene early.
