The challenge of making your home into a comfortable, safe space that you feel good about living in is that those efforts can also make it a comfortable, safe space for pests. Like you, rodents want somewhere warm where they can feast on the finest grocery store cereals your money can buy. By the time you actually see a mouse, however, theyve probably already been in your house for a while. The earlier you notice the signs of an infestation, the easier it will be to drive them out and prevent damageto both your home and your psychological wellbeing). The earliest signs that rodents are moving in can be subtle, so here are three things to watch out for.Telltale noises and odorsSome of the earliestand most easily overlookedsigns of rodents in your home involve your five senses. Rodents are excellent at staying out of sight, so early detection is crucial to prevent a full-blown infestation, Jim Fredericks, chief entomologist and vice president of public affairs at the National Pest Management Association, points out. Droppings, gnaw marks, and other visual signs offer clues, but he cautions you not to forget your nose. A musky odor in enclosed areas may signal the presence of rodents or their nests, he explains. The odor stems from the accumulating urine and droppings in closed-off, hidden areas of your home.Trust your ears, too. According to Aaron Carlson, district manager at Trutech Wildlife Service, the most common rodent infestations are rats, mice, and squirrels, and theyre louder than you think. The first thing homeowners tend to notice is noise associated with movement or gnawing, he says. Rats, mice, and squirrels have tiny claws that scrape against wood as they move.Mice can make a lot more noise than their small size might suggest, adds Fredericks. And because rodent teeth never stop growing, the pests need to wear them down by chewing. Any hard surface with a bit of give, like wood or plastic, is a target.Your pets are acting weirdIf you have cats or dogs in the house, changes in their behavior can be an early, sign that rodents have moved in without your permission. Dogs or cats will notice it more quickly than you will, notes Allan Bossel, pest expert at Bed Bug Exterminator. They might respond by being agitated. If your pet starts becoming very alert and restless, they might be sensing rodents around the house. One sign to watch out for is when your pets start to scratch at walls or sniff obsessively around specific areas of the house.Cats will sit and stare at the wall or ceiling (also near the range or refrigerator in the kitchen), particularly in the evening, notes Mieshelle Nagelschneider, founder and cat behaviorist at The Cat Behavior Clinic. Cats have a bionic sense of hearing and can hear mice giggle in the walls.Dont be overconfident that your cat or dog will sense mice: Carlson warns that while your pets might offer an early warning, theyre not entirely reliable. Animals will often completely ignore even obvious noises from rodents, he says.Suspicious stains and debris Credit: stockphotofan1 / Shutterstock.com Aside from sound, smell, and your pets, there are easily overlooked visual signs that rodents are creeping into your life, like unexplained debris around the house.This might include gnawed pieces of paper or cloth, which may indicate rodent nesting behavior, notes Bossel. While gnaw marks on food containers might be an obvious sign, gnaw marks elsewhere can be overlooked. Other places where gnaw marks might be visible are your furniture (especially the feet of wooden pieces), wires, storage boxes, and baseboards. You might also see small piles of shelled seeds or husks outside the home. Credit: Jay Ondreicka / Shutterstock.com Something subtle to look for: Marks on walls and baseboards. Rats and mice will explore a house for food and travel the same paths, notes Carlson. Smudges along the baseboards are a sign of rodent movement. The body oils and grease from their fur will leave rub marks along the walls.If you suspect rodents have invaded, the sooner you contact a professional pest control pro, the better. Early intervention is one of the most effective ways to manage rodent issues, Fredericks says. Rodents breed quicklyone pair of mice can produce dozens of offspring in just a few monthsso delaying action can result in a more extensive infestation thats harder and more costly to control.