An empty building in the middle of summer is the most pest-friendly your school will ever be. The doors are propped for deliveries and airflow. The HVAC is running on a reduced schedule, so humidity climbs in spaces that stay sealed and warm. Crews are tracking in and out, food shows up at the summer program and the front office, and the quiet, undisturbed corners that get walked past during the school year sit untouched for weeks. Every one of those conditions is an open invitation.
The trap is that the problem builds invisibly. Nothing looks wrong in July. Then the building fills up in August, the food and foot traffic spike overnight, and a population that established itself quietly over the summer suddenly has everything it needs to explode — right when classrooms are full and you have the least room to deal with it. The work to prevent that happens now, in the empty building, while you still can. Here are five things to stay ahead of.
1. Close the building's entry points before anything moves in.
Pests don't need an open door — they need a gap. A quarter-inch under an exterior door, a failed door sweep, a gap where a utility line enters the wall, a torn screen on a propped-open window, a loading-dock seal that's worn through. Summer, with the building empty and accessible, is the one time you can methodically walk the perimeter and close those gaps before the population that wants in actually gets in.
Walk the exterior and the loading areas with exclusion in mind. Check and replace worn door sweeps and weather stripping. Seal gaps around pipe and conduit penetrations with the right material for the gap — coarse stainless wool packed into the opening and sealed over holds up better than foam alone, which rodents chew through. Repair or replace damaged screens and damaged dock seals. Confirm that doors propped for ventilation during the day are actually closed and sealed at night, not left cracked. Exclusion is the highest-leverage pest work there is, because a gap you close in July keeps out everything for the whole school year.
2. Cut off water and food — the two things that decide whether pests stay.
A pest can get into any building. Whether it stays and multiplies depends on whether it finds water and food. Summer is when both quietly accumulate in places nobody's watching. A dripping fixture in a restroom that's not in daily use. Condensation pooling under an HVAC unit running on a reduced cycle. Standing water in a floor drain whose trap dried out. Crumbs and spills in a break room or summer-program kitchen that isn't getting the in-session attention. Cardboard and clutter in a storage room that holds moisture and gives cover.
Go after both. Fix the slow leaks and the dripping fixtures now — they're a maintenance item and a pest magnet at the same time. Keep drain traps filled. Make sure condensate is draining where it should and not pooling. Deep-clean the food areas that are still in use, and don't let summer-program food sit in open trash overnight. Get cardboard up off the floor and clutter out of the warm, undisturbed storage rooms where pests nest. A building with no water and no food is a building pests pass through instead of move into.
3. Inspect the quiet zones the school year never lets you reach.
During the year, the rarely-disturbed spaces are exactly the ones you never have time to check — the back of deep storage, the custodial closets, the mechanical rooms, the kitchen equipment that doesn't get pulled out, the auditorium and gym storage, the spaces above ceiling tiles near roof penetrations. Those are precisely where pests set up, because nothing disturbs them. Summer is when you can finally get into them.
Make an inspection pass through the quiet zones part of the summer plan. Pull equipment away from walls and look behind and under it. Open the storage rooms that stay closed and look at the floor-wall junctions, the corners, the dark base of shelving. Look for the evidence, not just the pest: droppings, gnaw marks, grease trails along baseboards, shed insect skins, egg cases, a musty or ammonia smell. Finding the early signs of activity now — when the population is small and the building is empty — is the difference between a targeted treatment in July and an infestation in September.
4. Work with your pest management provider on a real plan, not just a spray schedule.
If your district contracts pest control, summer is when that relationship should be most active, not least. The empty building is the ideal environment for thorough monitoring and treatment, and the reduced occupancy means treatments can be done with fewer constraints than during the school year. This is the season to move from reactive spraying to a real integrated pest management approach — monitoring, exclusion, sanitation, and targeted treatment only where it's warranted.
Get your provider in for a thorough summer inspection and ask for findings in writing: where there's activity, what's driving it, and what exclusion or sanitation work would close it off. Review the monitoring devices — where they are, what they're catching, what the trend is. Coordinate their treatment schedule with your cleaning schedule so the two support each other instead of working against each other. And in a K-12 setting, confirm that any products used and the schedule for using them meet your state's requirements for pesticide use in schools — many states have specific notification and integrated-pest-management rules for school buildings. The point is a documented plan you both work from, not a truck that shows up monthly and sprays the perimeter.
5. Document conditions and hand off a clear picture to the school year.
Whatever you find and fix this summer only protects the building if the knowledge carries into the school year. The slow leak you repaired, the entry point you sealed, the storage room where you saw early activity, the spots where the provider placed monitors — write it down and photograph it. That record tells the in-session team what to keep an eye on and tells you, in October, where to look first if something shows up.
Set the in-year cadence before you close out summer, too. Which areas get checked weekly, who's responsible, and how activity gets reported and escalated. Pest activity doesn't end when school starts — it just gets harder to address once the building is full. A team that walks into the fall knowing where the building's weak points are, with the gaps already sealed and the food and water sources already cut off, spends the school year staying ahead instead of catching up.
The bigger picture — summer is decided in July, seen in September.
Pest problems almost never show up when they actually start. They establish quietly in the empty, warm, accessible building of mid-summer and reveal themselves weeks later when the building fills with the food and traffic that let them thrive. By then you're managing an infestation in occupied classrooms instead of preventing one in empty ones.
The building teams that don't fight pests during the school year are the ones who did the unglamorous work in July: walked the perimeter and closed the gaps, killed the water and food sources, inspected the quiet zones, worked a real plan with their provider, and documented all of it. None of that work looks urgent in an empty building. All of it is what keeps September from turning into a problem you can't spray your way out of.
Talk soon, Daniel Mendoza Facility Insight
P.S. Pest work means chemical handling, ladder and confined-space access, and equipment most crews use only occasionally — all of it worth a documented safety talk. The K-12 Facilities Safety Talk Program gives you 24 ready-to-deliver safety talks plus an annual training log to record every session. Use them weekly or monthly, all school year. Get it here → — $37
P.P.S. Want the summer prevention walk as a checklist you can hand to the crew? It's part of the K-12 Summer Facilities Checklist Bundle — $27 →