What Are the First Signs of Rodent Infestations in a Warehouse?

We haven’t seen a live rodent, but think there could be a hidden nest in the warehouse. What are the first signs of a rodent infestation?

One of the first visible signs of a rodent infestation, whether mice, rats, or squirrels, is droppings. Fresh droppings tend to be dark and soft, while older ones become dry and faded. They may appear beside walls, behind stored goods, near loading bays, or around food and packaging materials.

Other early warning signs of rodents in a warehouse environment include:

• Gnaw marks on cartons, timber, cables, or plastic containers
• Torn packaging or unexplained product damage
• Grease marks along walls, pipes, and potential “travel” routes
• Shredded paper, insulation, or fabric used as nesting material
• Scratching or scurrying noises, particularly when the warehouse is quiet
• Musky, stale, or urine-like odors in enclosed areas
• Tracks or tail marks in dust
• Disturbed bait stations or monitoring devices

Employees may notice these signs before seeing a live rodent because rats and mice are often most active at night, or when the building is quiet. Daytime sightings can suggest a larger population or significant competition for food and shelter.

Warehouse managers should record the location and date of every sign identified. Isolate any affected stock and contact a pest control professional to carry out an inspection. Professional rodent inspections will typically include and outline key entry points, such as loading doors, roof spaces, drainage points, utility penetrations, and external storage areas. Responding to early evidence can prevent contamination, stock loss, and damage to electrical wiring or building materials.