Sometime in the next few weeks you will climb into the attic, pull down a stack of boxes, and carry them into the living room. Those boxes have been sitting in the dark, in Florida heat, untouched since January.

A lot can take up residence in eleven months. Most of it is harmless and easy to deal with if you look before you unpack. The problem is that almost nobody looks, and a sealed box carried straight into the house is a very efficient way to move something from the attic into the room where everyone sits.

Why an attic is a good place to live

Undisturbed is the key word. Pests do not need much more than warmth, darkness, and a long stretch of time when nobody comes near them. A South Florida attic supplies all three, and holiday storage supplies the fourth thing, which is structure to hide inside.

It is also the part of the house people visit least. What our technicians actually find in South Florida attics is rarely something the homeowner knew about, and the reason is simply that nobody had been up there since the last time they fetched the decorations.

Roof rats are the usual tenants here, and they enter at the roofline rather than at ground level. Our guide to rodent work before the season covers how they get in and why sealing is the part that lasts.

What cardboard is to a rodent

It is building material, not just cover. Rodents shred cardboard and paper for nesting, and a stack of storage boxes is a supply that never runs out. That is why a box that looks intact on the outside can have a hollowed-out cavity behind the wrapping paper.

The signs are easy to read once you know them. Shredded paper or cardboard fluff collecting in a corner. Droppings along the top of a box or on the floor beside it. Gnaw marks on a cardboard edge, which look like small parallel scrapes rather than a clean tear. A faint ammonia smell in a closed space.

If you find droppings and are not sure what left them, our guide on rat droppings versus mouse droppings covers the difference, and it matters, because the two need different treatment.

Roaches and the box problem

Cardboard is close to ideal for them. The corrugated layers give a tight, dark space to sit in, the glue and starch in the board are edible, and a stored box is never moved. That combination is why pest professionals treat cardboard storage as harborage rather than as containers.

There is a second problem specific to roaches, which is that they travel inside boxes. A box that has been in the garage or attic can carry egg cases as well as adults, and the egg case is the part people miss, because it is small, brown, and looks like a seed stuck to a seam or a fold.

American roaches, the large ones, mostly live outdoors and wander in. German roaches live indoors and breed indoors, which makes them the species you least want moved from one room to another inside a box. Our identification guide covers how to tell them apart.

What to check before a box comes inside

Why sealed bins do more than they look like they do

Switching containers removes two things at once. A sealed plastic bin takes away the nesting material and the harborage in the same move, and it does not absorb the humidity that makes cardboard attractive in the first place.

It also makes next year easier to assess. A clear bin can be checked at a glance without opening it, which is exactly the inspection most people skip.

If you replace boxes gradually rather than all at once, start with the fabric items and the light strings, since those are the ones where damage costs the most and gets noticed the least.

If you find something

Do not crush it and carry on. With roaches in particular, crushing spreads the allergenic material you would rather remove, and it tells you nothing about how many more there are. Our article on why squishing is the wrong move covers what to do instead for each pest.

Vacuum rather than sweep, and empty the canister outside. Put the affected box in the bin outside the house rather than back in the attic. Then look at where that box was sitting, because what you found in it almost certainly did not arrive in the box on its own.

One box with activity is a box. Several boxes with activity, or droppings on the attic floor between them, is an attic problem that storage containers will not solve.

The part people forget in January

Repacking matters more than unpacking. Everything that goes back up in January sits undisturbed until next November, so the state you leave it in is the state you will find it in.

Make sure nothing organic goes back into a box. Food-adjacent items are the common mistake here, along with real greenery, wreaths with berries, and anything that was used near food on the day. Seal bins properly rather than resting the lid on top, and keep the stack off the attic floor and away from the walls if you can.

If the house is closed up for part of the year, this matters more again. Our guide on opening a South Florida home after months away covers what a long empty stretch does to a house.

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