The items you store matter more than you think for keeping insects out

Bugs move into storage units because they find food, moisture, or shelter. You can't eliminate all three, but you can remove the easiest targets. Store only items that don't attract pests—avoid anything with food residue, cardboard boxes that hold moisture, and unsealed containers. Use airtight plastic bins, keep the unit as dry as possible, and leave space between stacked items so air can move. Most insects need either a food source or high humidity to survive; removing both makes your unit an unappealing place to live.

The specific bugs you'll face depend on your climate and the unit's location, but the prevention method stays the same: deny them what they need. A storage unit in a humid climate near trees will attract different pests than one in a dry area, but both can be protected by the same basic steps.

Key Takeaways

  • Store items in sealed plastic bins rather than cardboard boxes, which absorb moisture and break down over time, creating hiding spots for insects.
  • Remove anything with food residue—even crumbs in old boxes or residue on dishes—because roaches, ants, and beetles will travel to your unit for a single food source.
  • Keep the unit as dry as possible by using desiccant packets or a small dehumidifier, since most storage pests need moisture to breed.
  • Leave space between stacked items and avoid pushing boxes against walls, which traps moisture and creates sealed environments where insects hide.
  • Inspect items before storing them and check your unit every few months, because early detection stops a small problem from becoming an infestation.

What not to store: food and food-stained items

Never store anything with food residue, even if it seems clean. Roaches, ants, beetles, and moths can smell food particles invisible to you. This includes dishes that were used but not thoroughly washed, takeout containers with dried sauce, and boxes that once held food. If you're storing kitchen items, wash them completely and let them dry before packing.

Pantry items like flour, sugar, rice, and cereal attract multiple types of insects and should not go into storage at all. If you must store dry goods, use airtight glass or plastic containers with locking lids, not the original packaging. Cardboard boxes and paper bags are permeable—insects can chew through them or squeeze through tiny gaps. Even sealed cardboard eventually breaks down in humid conditions, creating entry points.

Pet food, bird seed, and any animal feed are major attractants. Store these at home or in a climate-controlled garage, not in a storage unit. The smell alone will draw insects from a distance.

Use plastic bins instead of cardboard boxes

Cardboard absorbs moisture and deteriorates over time, especially in humid climates or units without climate control. As the cardboard weakens, it creates gaps and soft spots where insects can enter and hide. Plastic bins with tight-fitting lids seal out moisture and pests. They're also stackable, which saves space, and you can see inside without opening them.

Choose bins made of rigid plastic at least 1/8 inch thick—thin plastic cracks and warps in temperature swings. Make sure the lids seal completely; test them by pressing down until you feel resistance. Label each bin on the outside and keep a list at home of what's inside, so you don't have to open bins unnecessarily.

If you have items that can't go in plastic bins—like furniture or artwork—wrap them in plastic sheeting or plastic furniture covers, not cloth. Cloth absorbs moisture and provides a surface where insects can lay eggs. Seal the plastic with tape so insects can't crawl underneath.

Control moisture with desiccants and ventilation

Most storage unit insects need moisture to breed. Roaches, silverfish, and many beetles thrive in humidity above 50 percent. You can't control the outside climate, but you can reduce moisture inside your unit by using desiccant packets and leaving space for air to move.

Place desiccant packets—the silica gel packets that come in new shoes or vitamins—throughout your unit. You can also buy bulk desiccant packets online or at hardware stores. Replace them every few months or when they feel damp. For larger units or very humid climates, a small electric dehumidifier designed for storage spaces works better than packets alone. Plug it into an outlet if your unit has one, or use a battery-powered model.

Never seal your unit completely. Leave a small gap at the door or use a door sweep that allows air to circulate but blocks insects from entering. Stagnant air traps moisture. Stack items so there's at least a few inches between boxes and the walls, and don't push everything into one corner. Air movement prevents moisture from pooling in one spot.

Space items apart and away from walls

Insects hide in tight spaces where they feel protected. Pushing boxes against walls and stacking them floor to ceiling creates the perfect environment—dark, undisturbed, and often damp. Leave at least 6 inches between the back of your items and the wall. This gap lets you see if pests have moved in and allows air to circulate.

Don't stack boxes directly on the floor. Use plastic pallets or wooden pallets treated with insecticide (check the label to confirm it's safe for storage). Pallets lift items off the ground, where moisture collects and insects breed. If pallets aren't available, use plastic shelving units, which are cheaper and easier to clean than wood.

Create an aisle down the middle of your unit so you can walk through and inspect items. This also improves air circulation. When you check on your storage every few months, you'll spot signs of pests—droppings, chewed cardboard, or dead insects—before they spread.

Inspect items before storing them

Bugs often hitchhike into storage units inside boxes or furniture you're moving. Before you pack anything, look for signs of existing infestation: small holes in wood, droppings that look like pepper, egg cases, or live insects. Furniture from basements, attics, or garages is especially risky because it may already harbor pests.

If you find signs of infestation, treat the item before storing it. For wood furniture, a professional pest control service can heat-treat or fumigate it. For fabric items like upholstered chairs, freezing them for several days kills most insects, though this works best for items you can fit in a home freezer. Wipe down hard surfaces with a damp cloth to remove any eggs or debris.

Clothing and linens should be clean and dry before packing. Wash them in hot water if possible, and store them in sealed plastic bins with a desiccant packet. Insects like moths and carpet beetles lay eggs in fabric, especially if it's been worn and has body oils or food stains.

Check your unit every few months

Even with prevention, occasional insects may still find their way in. Early detection stops a small problem from becoming an infestation. Visit your unit every two to three months and look for signs of pests: droppings, dead insects, chewed cardboard, or musty smells that suggest moisture buildup.

If you spot a few insects or minor damage, you can often handle it yourself. Wipe down affected areas with a damp cloth, replace desiccant packets, and improve ventilation. If you see a large number of insects, active nests, or widespread damage, contact your storage facility manager when ready. Many facilities have pest control contracts and will treat the unit at no cost to you.

Keep a straightforward log of your visits—just the date and whether you noticed any problems. This helps you spot patterns, like moisture building up in summer or insects appearing after heavy rain.

Frequently Asked Questions

Can I use mothballs or cedar to keep bugs away?

Mothballs kill some insects but only in sealed containers—they don't work in open storage units because the fumes dissipate. Cedar chips repel some moths and beetles but aren't reliable on their own. They work best as one layer of protection, combined with sealed bins and low moisture. Replace cedar chips every few months as the scent fades.

What if my storage unit doesn't have climate control?

Non-climate-controlled units are more prone to moisture and temperature swings, which attract insects. Use more desiccant packets than you would in a climate-controlled unit, and check on your items more often—every month or two instead of every few months. Plastic bins and pallets become even more important because they protect against both pests and humidity.

Are there bugs I should worry about more than others?

Roaches, silverfish, and carpet beetles are the most common storage unit pests. Roaches need food and moisture, silverfish need moisture and starch (paper and cardboard), and carpet beetles lay eggs in fabric. Prevention is the same for all three: remove food, use plastic bins, control moisture, and inspect regularly.

Should I spray insecticide in my storage unit before moving items in?

Spraying an empty unit may kill insects already present, but it won't prevent new ones from entering. The spray breaks down over time and won't protect your items for months. Focus instead on the prevention methods that work long-term: sealed bins, low moisture, and regular inspections. If you're concerned about existing pests, ask your storage facility if they treat units before move-in.

Can I use plastic wrap instead of bins?

Plastic wrap protects items from dust but not from insects, which can chew through it or crawl underneath. Wrap is useful as a second layer over bins or furniture, but it shouldn't be your only protection. Rigid plastic bins with locking lids are much more effective because they seal completely and are harder for insects to penetrate.