To protect your home from rats, it helps to understand how they actually behave. Rats are far more capable than many people think – they climb, swim, gnaw through hard materials and learn quickly from their surroundings. Here we go through rats' habits, abilities and movement patterns, and what that means for keeping them away.
Quick answer: Rats are nocturnal, shy and highly adaptable. They climb walls and pipes, swim well and can squeeze through gaps of just 2 cm. They follow fixed runways along walls, avoid new objects and have excellent smell and hearing but poor eyesight. Understanding the behaviour lets you seal the right places and position measures where the rats actually move.
Can rats climb walls?
Yes, rats are skilled climbers. The brown rat climbs up rough façades, brick, downpipes, cables and nearby trees. The black rat (roof rat) is an even better climber and readily moves high up – in roofs, attics and along wiring. That's why rats can get into the house well above ground level, not just at the foundation. Their climbing ability means bushes and trees against the façade act as ladders straight up to the roof.
Can rats swim?
Yes, and considerably better than you'd think. The brown rat is an excellent swimmer, can hold its breath for several minutes and swim long distances. That's why rats can, in rare cases, come up through the drainage system and even through the toilet, especially in older properties. A non-return valve in the drain reduces the risk.
How do rats get in – and through how small an opening?
Rats have soft, flexible bodies and can squeeze through an opening of just 2 centimetres. They also gnaw constantly to file down their teeth and get through wood, plastic, thin sheet metal and insulation – but not steel or concrete. Common entry points are cracks in the foundation, gaps around pipes, vents without mesh and damage at the eaves. If you want to understand the whole picture around rodents in the home, read the guide to rats in the house.
Runways and movement patterns
Rats have poor eyesight and navigate using smell, touch and memory. They therefore follow fixed runways along walls and obstacles, keeping their body against a surface. Over time their fur leaves grease marks along these paths, often a few centimetres up. These trails show exactly where the rats move – and are the best places to set traps or preventive measures. Rats are also neophobic: they are suspicious of new objects and may avoid a freshly placed trap for several days before daring to approach.
Shy, nocturnal and smart
Rats are mainly active at dusk and in the dark, when they move most safely. They are intelligent, have excellent smell and hearing and quickly learn to avoid dangers. If you see a rat in the middle of the day, it's often a sign of a larger infestation or that the nest has been disturbed. Their shyness is also why rats are usually detected through their traces – droppings, gnaw marks and sounds – rather than by seeing the animals. Unsure whether it's rats or mice? Read about the difference between rats and mice.
What the behaviour means for protecting your home
Since rats climb, swim and squeeze through small gaps, sealing at ground level alone isn't enough – also check roofs, vents and pipe penetrations higher up. Place traps and measures along the walls where the runways run, not in the middle of the room. And expect that neophobia means it can take a day or two before the rats approach a new trap. A preventive, poison-free complement is an electronic rat repeller that makes enclosed spaces unwelcoming with ultrasound and bioacoustic signals.
What to do now
Use your knowledge of rat behaviour as a map: look for grease marks and droppings along the walls, check both low and high entry points and put measures where the rats move. Go through all the signs of rats to confirm the infestation and act in time.
\nFrequently asked questions
Can rats climb walls?
Yes. The brown rat is a skilled climber and scales rough façades, pipes and cables. The black rat is even better and readily climbs high up, which means rats can get in via roofs and attics.
Can rats swim up through the drains?
Yes. The brown rat is an excellent swimmer and can hold its breath for several minutes. In rare cases it comes up through the drains and toilet, especially in older properties.
What time of day are rats active?
Rats are mainly nocturnal and move most at dusk and in the dark. If you see a rat in the middle of the day, it may indicate a larger infestation or that the nest has been disturbed.
