Tenants unknowingly could bring mice with them. This can happen if they are relocating boxes from their garage at home to their storage unit during the late fall or winter. There is usually little evidence of a family of mice that have recently relocated indoors for the winter. They will find refuge in any open box or bin. Upon being relocated to a storage unit the boxes are reconfigured. If this cuts off their escape route, the mice will soon die. This will result in the unpleasant experience of finding a family of dead mice within your belongs.
At both of our storage facilities we have plenty of rules of what not to store, and how not to store it, so there really should never be any issues with mice in the units. However (particularly in the winter) if the rules and advice are not followed you can definitely end up with problems. If you fully understand and follow three basic rules this issue could be largely eliminated: NO FOOD, NO PLACE TO NEST, PROTECT YOUR BELONGS BY SEALING BOXES SHUT.
FOOD Mice are always on the search for food. In a natural setting, they prefer small seeds from native plants and grasses. However, mice are omnivores and will gravitate to the easiest source of food available. They have a keen sense of smell so they will chew through boxes and bags to get to food. As I will discuss below, things that smell like food (real or not) will also attract them. Invariably some of your stuff will smell good to a mouse. So a trick we learned is to distribute Bounce brand fabric softener sheets throughout your unit. For whatever reason the mice seem to hate this smell.
SHELTER In the summer mice may find it better to nest outdoors in order to be closer to their natural food source. However, in the winter an indoor nest may suit them much better. A box with a small opening is basically a pre-made nest to a mouse! It is very important that you seal all of your boxes and other containers. Any small opening could be their access to a perfect winter shelter. Mice have the ability to get in through very small openings. Youtube has videos of adult mice squeezing through holes smaller than a wedding ring, and wikipedia says adolescent mice can fit through holes the diameter of a pen. Also, do not supply these rodents with nest building materials. These would include a very broad list of anything that is soft enough to chew and turn into bedding. Newspapers, cloth, feathers, insulation, foam, styrofoam, packing peanuts, leaves, grass, etc etc will all work just fine in building a nest. With these material, a mouse can utilize any confined area like a crack or corner to build a nest. Mice like small confined areas with limited access to protect them from predators. We recently had a tenant discover mice in an open crate that contained soft, fluffy dog toys. Obviously this was perfect [ready made] nest for the mice to tough out the winter.
ANECDOTES About 4 years ago, I had parked my truck under a covered shed while we were vacationing in Hawaii. It was on a large property that bordered undeveloped land on the outskirts of Bend. A friend had warned me of the risks of pack rats nesting in the truck. Sure enough, after returning home, I had discovered a moma pack rat, and 3 babies nesting up under the intake manifold. This family was undeterred by that fact that I had been driving all over Bend (including on the freeway). I actually did not discover them until about two weeks after returning home! If you have ever seen a pack rat up close, they are actually very beautiful. The more I learned about them, the less I wanted to kill them, but they had already begun chewing my insulation, hoses and wires. When I shared this story with our landlord (at the time) she became very concerned that the pack rats would relocate from my truck into the house. Sadly, I set a large rat trap and killed the mom. My point here is that rodents can live in your home, garage, car, or storage unit. And they can unknowingly be transported with you when you relocate.
A tenant complained that mice had gotten into her unit. This happened in the middle of winter when mice are most likely to seek inside shelter. The unit had chewed packing peanuts, and mice droppings in her boxes. This tenant thought she had properly packed here belongings, but she was actually creating perfect nests for mice. Her boxes had holes at the top that were the handles. This is common with file boxes. And they were filled with packing peanuts. The particular “peanuts” she used were biodegradable, corn based, puffed peanuts. So, in addition to the packing material being excellent insulation material for nest building, they were sweet smelling and edible as well. The manufacturers of these biodegradable peanuts claim that they don’t “attract” rodents because they have no “nutritional” value. However, they will go on to say that they are made from corn, have a pleasant smell of popcorn. A rodent will see this as food, regardless of its “nutritional value”. I think it is fair to say that some of the [human] food we buy also has no real nutritional value, but we will still find reason to eat it. The old Styrofoam peanuts also make great nesting material, but I believe the smell of the corn based biodegradable peanuts will lead the mice directly to your unit. Again, the use of Bounce Sheets can help deter the mice. Be sure to seal tape all openings in your boxes.
The very nature of “Self Service” style storage facilities is that the tenant has to take responsibility for the well-being of their contents. This includes (but is not limited to) unfortunate events that might occur because your neighbors are not following the rules. Both of our facilities are built to the same high standards as the other 20+ facilities here in Bend. At Powers Road Self Storage we have a total of 550 units. The access is 15 hours a day, 7 days a week. So as much as we would like for our tenants to follow the rules they are impossible to fully enforce. We encourage you to take your time packing to to make sure no hidden granola bar is forgotten in your camping gear or hidden cookie under a sofa cushion. Donate your food when moving to a friend of food bank. Clean items well that could have a residual food smell on them.
You have to make sure that your cardboard boxes are taped shut. For this reason I recommend that you keep a utility knife and a roll of packing tape in your unit. If you have items that you know you will frequently need, then utilize plastic bins with lids. If you still feel your contents are at risk I strongly recommend that you keep two mouse traps set in your unit. The best location for these is at the front of the unit near the roll up doors. Poison will kill mice, but they will likely die inside your unit, and they can really stink. Mice can migrate from unit to unit along the 1 ½” step down that is at the front of the “Exterior Access” storage units. The “Interior Access” units are far less likely to have rodent issues.
The bottom line is that you can never completely eradicate rodents. But with common sense, and some [not-so-common] sense you can greatly minimize any risk of damage to belongings stored in your garage at home, or a self storage unit. Set traps and disburse Bounce Sheets throughout your unit. If your unit has no food, no place for the mice to nest, and you have properly sealed and protected your belongings, then you will likely never have an issue.