Pests in Storage Units: What Gets In, What They Destroy, and How to Stop Them

I manage 340 units across two locations in Central Florida. We deal with pest complaints every single week. The conversation is always the same: tenant opens their unit after three months, finds mouse droppings on everything, chewed-up photo albums, and carpet beetle larvae in the winter clothes. Then they want to know why we didn't prevent it. Here's the truth about what you can and can't control in a storage facility.

Mice Are the Biggest Problem

A mouse can squeeze through a gap the width of a pencil. Storage units have roll-up doors with rubber seals that wear out, wall panels that don't sit perfectly flush, and concrete floors with expansion joints. Even a well-maintained facility has entry points.

One mouse can shred a box of documents in a single night. They chew constantly because their teeth never stop growing. Paper, cardboard, fabric, photos, book bindings, leather -- all fair game. The damage compounds fast because mice reproduce in 20 days and a female has 5-10 litters per year.

Dropping a few snap traps in your unit won't fix a building-wide rodent problem. If mice are getting into the facility itself, that's on the management to handle with professional exclusion work. Your job is making your unit less attractive than the one next door.

Roaches Travel Through Walls

Interior storage units share walls. If the tenant in unit 247 stored a couch from a roach-infested apartment, those roaches will spread to adjacent units through gaps in the wall panels. Climate-controlled buildings are worse for this because roaches prefer the stable temperature. I've seen German roach infestations jump 8 units in a single hallway.

There's not much you can do about this besides choosing a facility that sprays common areas regularly and responds to complaints quickly.

Pests That Arrive With Your Stuff

Half the time, you bring the problem with you. Indian meal moths come in with any stored food product -- flour, rice, pet food, birdseed, even potpourri. Carpet beetles come in with wool clothing, rugs, taxidermy, and animal-fiber blankets. Clothes moths do the same. These insects were already in your stuff before it went into the unit.

Stored product pests are sneaky because the damage happens slowly. You won't see holes in a wool coat for months. By the time you notice, larvae have been feeding the entire time.

The Rules for Packing a Storage Unit

These aren't suggestions. Treat them like facility rules because they're the difference between pulling out clean belongings and pulling out garbage.

No food. Period. That includes pet food, birdseed, candy, spice racks, and anything edible. If mice smell it, they will find it.
Plastic bins, not cardboard. Mice chew through corrugated cardboard in under a minute. Use snap-lid plastic totes. Sterilite and Rubbermaid both work. Worth every penny.
Elevate everything. Nothing sits directly on the floor. Use cheap plastic shelving or wooden pallets. Four inches of clearance lets you spot droppings or insect activity without unstacking everything.
Mothballs for wool and fabric. Place mothball packets (paradichlorobenzene type, not naphthalene) inside sealed containers with wool blankets, coats, and sweaters. Don't scatter loose mothballs around the unit -- they only work in enclosed spaces where the vapor concentrates.
Leave walking space. Pack with a narrow aisle down the center so you can walk in and check conditions without pulling everything out.

Climate Control Helps, But It's Not Bulletproof

Climate-controlled units stay between 55-80 degrees year round. That reduces moisture, which means less mold and fewer moisture-loving pests like silverfish and springtails. But roaches and mice do just fine at 72 degrees. Climate control is worth paying for if you're storing wood furniture, electronics, or documents, but don't assume it solves the pest problem.

Check Your Unit Monthly

Visit your unit at least once a month for the first three months. Walk in, look at the floor for droppings, check the corners for cobwebs and egg sacs, sniff for musty odors. If you find evidence of mice or insects, report it to management immediately and document it with photos and dates. Your storage insurance claim (if you have one) will need documentation.

After three clean monthly checks, you can stretch it to quarterly. But never go longer than 90 days without looking. The tenants who store-and-forget for a year are the ones who end up with the worst losses.