“I think we have bedbugs.” 

Those six words are something nobody — whether you’re a homeowner, a renter, or a wary hotel guest — wants to hear. Bedbugs can multiply pretty quickly, so your best bet to keep your mattress bug-free is to know the signs so you can act quickly — and replace your mattress if you need to.

Does your mattress have bedbugs? Three ways to know

Nobody wants to deal with a bedbug infestation — let alone one that’s gone unnoticed for any length of time. Costs to treat larger infestation issues can skyrocket up into the thousands, so finding — and treating — an infestation early is absolutely in your best interests.

Think of the most obvious sign of bedbugs. If you said insect bites, you’d be partially right. Once bedbugs get into your home, it’s possible you’ll wake up one morning with mysterious bed bug bites. But there are a few problems with that line of thinking: 

• You may not notice you’ve been bitten until red welts appear hours or even days later.
• Although nocturnal, bedbugs don’t necessarily feed every night — it could take days or weeks before you notice bedbug bites.
• Bedbug bites can look similar to other insect bites — if confused with mosquito or flea bites, you may not think to check for bed bugs until other symptoms crop up.

If you want to identify a bedbug infestation quickly, here are three clear indications of the tiny bloodsucking pests.

Dark spots or stains on your mattress

Spotting a bedbug infestation early is your best bet for resolving the problem before it gets out of hand. Since bed bug bites can be confused with other types of insect bites, they shouldn’t be the main thing you look out for. Instead, look for physical signs of a budding infestation such as noticeable stains or spots on your mattress.

If you notice reddish stains on your bed sheets, this could be your first sign of a bed bug infestation. It’s not pleasant to know this, but it’s worth it to be prepared: These stains are likely the result of crushed bedbugs and an indication that you should take a closer look at your mattress.

Another sign of a bed bug infestation that is more likely to catch your eye is one or more dark spots on your sheets, pillows, or mattress. If bedbugs are the culprit, these tiny spots are insect excrement. Although they are likely to be no bigger than the period at the end of this sentence, they can bleed or smear on your bedding’s fabric.  

Signs of bedbugs around the home such as eggs, eggshells, or clusters of small insects

Although they are very small (adults typically grow as large as an apple seed, or approximately one fourth an inch), bedbugs aren’t invisible. If your bedroom is already host to a group of unwanted insects, you may notice small groups of live insects or their shells. 

These can crop up on your mattress, but that’s not the only place you should look. Due to their small size, bedbugs can hole up in any number of small crevices or cracks during the day. If you woke up with mysterious bug bites and want to rule out a bedbug infestation — or simply want to do a thorough double check — look for clusters of super-tiny insects in or around the following areas:

• Window frames
• Electrical outlets
• Floor molding with noticeable gaps
• The seams of chairs or couches
• Wooden drawers or dressers

A sweet yet musty odor in or around the bedroom

Hopefully you never encounter this indication of a bedbug infestation, as it takes a large number of insects for an odor to develop. It’s crucial to recognize this smell for what it represents, however, so that you can act quickly to tackle your infestation.

Orkin pest control describes this odor as “a musty, sweet smell, often likened to berries.” It may present as a sweet, yet distinctly unpleasant, scent. If you get a whiff of this musty odor, it’s likely time to seek professional help to address your bed bug infestation — or just replace or mattress to be on the safe side.