Your home can attract the attention of all sorts of creatures, from insects to rodents, but not all of them make their presence known by scratching sounds in the walls or droppings left on the floor. Many pests are more subtle, and this can make them more dangerous. Without obvious signs of an infestation, you may not realize you have one until they've already been there a while. Here are four things you should look out for that could signal an infestation of some kind.

1. Piles of Frass

Frass is an excrement produced by many types of termites, and is often mistaken for sawdust due to its proximity to wood and its tendency to match the color of surrounding wood. Regardless of its name, however, if you see small piles of what look to be sawdust in your home -- especially in your garage or near walls -- this is a strong sign you might have a termite infestation. You can double check this assumption by looking for small piles of wings, which are left by termites that have just formed a new colony, or by tapping on wood near the frass piles to see if they sound hollow.

2. Constant Foul Odor

If your home is subject to a foul smell that just won't go away, it could be a sign there are creatures nesting in your home. Odds are also good they've situated themselves somewhere near your home's ventilation system, as air ducts are sometimes used as nests or end up as traps for rodents. First, investigate your attic, your furnace, your air conditioner, your vents, and your ducts. However, even if you remove anything you find there, whether it be a nest or creatures themselves, you should still call an exterminator. Those creatures probably planned to stay, and that often means multiplication.

3. Wiring or Electrical Issues

Many types of rodents like to chew on just about everything, and this includes wires and cables. If you find constant damage to certain parts of your home's wiring, or if you have electrical issues that won't stay fixed for more than a week or so, you may have a creature living nearby constantly gnawing on any wires or cables it can get close to. The damage may be obvious, but only if it's in a place you can see. Some rodents may nest in the attic or other places you don't typically go, making it harder to detect until the damage is already done. If you have an infestation, this damage will likely reoccur until the creatures are exterminated, so call a professional if you experience repeat electrical issues.

4. Signs of Nesting

In less-frequented areas of your home, some buildup of dust and debris is natural. Nests are often created with whatever materials its occupants can get, which can result in a combination of shredded paper, leaves, twigs, dust bunnies, and other items. These aren't always obvious upon a cursory search, as they blend in with their surroundings and are often made in dark, closed-in spaces. Take some time to search your attic, basement, and any other small, enclosed spaces you don't normally visit. Also, don't forget to check under your appliances and under the hoods of unused machinery or vehicles or behind piles of objects near your home.

​If you think you have an infestation, contact an exterminator for pest services.