Nobody wants to roll open their storage unit door to find holes gnawed in Grandma’s wedding dress, bed bugs infesting the sofa and cockroaches scuttling through boxes. Storage units full of cardboard, upholstery, cracks and crevices scream “home” for rodents and insects.

“Storage units are especially vulnerable to pest infestations because, unlike a house or an office, they can go a long time before the renter or storage unit owner checks,” says Ryan Michel, owner of Defense Pest Control in Mesa, AZ. “This means an infestation can grow undetected, and can easily spread from unit to unit.”

Because rodents reproduce quickly, a small infestation can become a big problem in a matter of weeks. One pregnant mouse living in your storage unit can lead to a costly infestation and ruined possessions. Cockroaches, ants and bed bugs are equally destructive.

So, how can you keep pests out of your self storage unit? Here are 9 tips for pest-free possessions.

1. Ask Facility Staff About Pest Control.

Ask about pest control before you rent a storage unit.

“High-quality storage facilities have agreements with pest companies to treat the unit and make it a lot harder for pests to find their way in and find their way from unit to adjacent unit,” says Michel.

2. Scope Out the Grounds.

Make sure the storage facility keeps shrubbery and  other landscaping trimmed away from your unit, says Bethany Beck, marketing coordinator with Sparky’s Storage Solutions in Amarillo, TX. Check whether garbage bins are sealed and disposed of regularly.

3. Consider Containers.

Avoid using cardboard boxes that can easily be infested and used by nesting rodents, Use sealed plastic containers instead, says Beck. Not only do stackable plastic bins take up less space, they’re much more difficult for pests to invade.

4. No Food Allowed.

Clean kitchen items thoroughly, especially appliances that have food residue on them, before storing, says Beck. Never store food in your unit. When moving your stuff in, save the sandwiches and pizza for your helpers AFTER you finish moving. Crumbs left behind can lead to pest problems.

5. Raise Stored Items.

Beck recommends storing boxes on raised pallets to prevent smaller pests from hiding underneath.

6. Wrap Upholstered Furniture.

Wrap plastic around upholstered furniture and soft items like pillows or curtains that don’t fit into boxes.

“Moths love to destroy fabric, and a layer of plastic will make it harder for rats to damage your belongings,” says Michel.

7. Use Pest Deterrents.

Cotton balls soaked in peppermint oil or lavender and cedar blocks are natural pest deterrents, says Michel. You can also use conventional bug sprays and set mouse or rat traps along the inside walls and near the door.

8. Stay on Top of Pest Control.

“Check on your unit regularly and look for signs of infestation,” says Beck.

If you notice any problems, report them to the facility manager immediately.

9. Call in an Expert.

Hire a pest professional as soon as you suspect a pest problem.

“They are going to be able to assess the extent of your problem, help you with treatment and offer suggestions to prevent further damage from occurring in the future,” says Michel.