Mold is one of those hidden dangers in your home that can sneak up on you, often in places you least expect. While it’s easy to assume mold only thrives in damp basements or dirty bathrooms, it can actually grow in a variety of other spots in your home. Whether it’s lurking under a doormat or on your kids’ bath toys, all it takes is a little moisture and a lack of airflow for mold to flourish. We’ve gathered a list of five common—but surprising—spots where mold is likely to hide, with a few simple tips on how to prevent it from taking hold.

1. Under Doormats

It can be easy to walk past your doormat each day after wiping mud, grass, and snow from your shoes. But if the weather’s been especially wet, or if your doormat sees heavy traffic, it could be harboring mold. Moisture from daily use can get trapped underneath, creating the perfect environment for mold and bacteria to grow. For proper maintenance, rinse it regularly and be sure to lift it off the doorstep so both the mat and the surface underneath can dry properly.

2. Inside Filing Cabinets

If your house tends to have high levels of humidity, it’s important to keep an eye on any important documents you’ve stored away. Paper is an ideal breeding ground for mold, especially when tucked into a filing cabinet that’s rarely opened or moved. Unfortunately, once mold settles into paper, it’s difficult, if not impossible, to remove, so it’s best to prevent mold growth before any lasting damage occurs. If possible, avoid storing paper items in damp spaces like boxes, attics, or basements. Running a dehumidifier in your office during the muggiest months of the year can also help keep mold at bay.

3. Houseplants

As it turns out, overwatering your houseplants can be just as damaging as underwatering them. If you’re a fan of potted plants, you’ve probably heard of or even experienced root rot; plants can also develop mold from too much water. Excess moisture and poor air circulation in consistently wet soil create the perfect conditions for mold spores to thrive. To keep mold away from your plant soil and the surface of your pots, be extra mindful of your pours from the watering can.

4. Inside Toothbrush Holders

Toothbrush holders are essential in the bathroom. Nobody wants their toothbrush bristles touching dirty surfaces or falling into unsanitary places. However, the water that drips from your toothbrush can turn the inside of your toothbrush holder into the perfect environment for mold. To prevent mold buildup and keep your toothbrush area clean, be sure to rinse and dry your toothbrush holders regularly.

5. In or on Children’s Toys

Small children have a habit of putting just about anything in their mouths—including their toys. This can lead to large gatherings of bacteria and moisture, which can quickly create a welcoming home for mold. Bath toys, in particular, can be prone to mold growth if not properly maintained. For safe and sanitary playtimes, make sure to regularly clean your kids’ toys or send them through a hot water dishwasher cycle if they’re dishwasher-safe. A proper, well-ventilated storage space will also help to keep mold away.