Signs of Bed Bugs

The thought of having bed bugs can be distressing and it is not made easy by the fact that in the early stages of bed bug activity, detection can be very difficult as the bugs are small, well hidden in cracks and crevices and are active only at night when we are asleep.

The main bed bug signs are small, itchy red bites often in lines or clusters on exposed skin. This is one of the early signs of bed bugs and indicates that you may need to look further. You can also look for physical evidence on bedding and furniture, including:

• Rusty/reddish blood stains (from crushed bugs).
• Tiny dark spots (bed bug excrement).
• Pale yellow shed skins (casings).
• A distinct, musty odour in heavy infestations.

Bed bugs are notoriously difficult to eliminate, so confirming an infestation and taking swift, decisive action is critical to preventing their rapid spread. These resilient pests can multiply quickly and hide in the smallest crevices, making early detection a key factor in successful pest control. Moreover, if left untreated, even a minor bed bug problem can escalate into a severe infestation.

Bed bug infestations often go unnoticed in their early stages due to the insects' elusive nature; however, there are five key signs of a bed bug infestation that can help you identify their presence more confidently. Let’s look at all 5 primary signs in more detail:

While not a definitive sign (as other insects bite), bed bug bites are often a first clue. They typically appear as small, red, itchy welts on exposed skin, frequently arranged in a line or cluster (sometimes called "breakfast, lunch, and dinner" patterns) as the bug bites multiple times. Reactions can vary, and some people may not react at all.

These spots are small smears of blood left behind when a feeding bed bug is accidentally crushed as you move in your sleep. They will typically appear as tiny, red or rust-coloured smudges on your sheets, pillowcases, or mattress.

Look for very small, dark black or reddish-brown spots (about the size of an ink spot) that look like a marker has bled onto the fabric. This is bed bug excrement. Check mattress seams, box springs, and the bed frame. If you suspect a spot is excrement, you can test it: if it smears like digested blood when rubbed with a damp cloth, it is likely from a bed bug.

Bed bugs shed their outer shell (exoskeleton) typically five times as they grow from nymphs to adults. These castings are empty, translucent, and pale yellow-brown husks that look like a tiny, empty version of the bug itself. Finding these in crevices of your mattress, headboard, or furniture confirms that juvenile bed bugs are present and growing.

A heavy or long-standing infestation can produce a distinct, unpleasant, musty odour. It is often described as a sweet, sickly, or sometimes woody, coriander-like smell. This scent comes from the chemicals the bugs release from their scent glands. This is often released as an alarm pheromone when they are threatened. Bed bug droppings, digested blood, and shed skins can also create a sweet, musty smell, sometimes described as rotten raspberries.

To effectively check for bed bugs and help prevent a minor problem from becoming a full-scale infestation, we recommend using our thorough 3-Point Inspection Method. This approach focuses your search on the places where bed bugs are most likely to hide and ensures that you don’t miss crucial signs. The majority of infestations begin and are easiest to spot either on or immediately surrounding your bed.

Mattress seams and piping remain the single most likely place to find bed bugs in any sleeping area. These tiny pests prefer to hide in tight, dark crevices close to their food source, making the narrow borders and folds of a mattress an ideal habitat.

Strip the bed completely, then shine your torch or flashlight along all the mattress seams, tufts, folds, and the label/tag. Use a strong flashlight or torch and a credit card or similar tool to press along these hidden edges - doing so can dislodge the insects or help reveal clearer signs of their activity.

Looking for:

• Tiny dark black/brown spots (bed bug excrement)
• Red or rusty blood spots (from crushed bugs)
• Pale, translucent shed skins (casings)
• Live bed bugs (adults are about the size of an apple seed and reddish-brown)

Bed bugs often hide deep within the bed frame, making them difficult to detect at first glance. Consequently, you should:

• Lift or turn your mattress to thoroughly inspect the entire bed frame and structure
• Focus especially on inspecting the wooden frame, particularly the joints and corners as these offer ideal hiding places for bed bugs
• Shine your light into any cracks, screw holes, or gaps in the bed frame and headboard to help reveal tiny signs of bed bug activity, such as dark excrement spots or shed skins. 
• Use the edge of a credit card to scrape along these crevices - this can flush bugs out or reveal excrement marks

This careful, systematic inspection is essential, as bed bugs can quickly spread from these hard-to-reach areas if not promptly identified and addressed. 

If the infestation has been around for a while, they will likely have spread. Bed bugs are adept at hiding and can quickly move beyond your bed into nearby furniture, baseboards, and even behind wallpaper.

It becomes essential to check not only your mattress and bed frame but also the seams and folds of upholstered chairs, couches, and headboards. Moreover, check drawers (undersides as well), bedside cabinets, nightstands, and the cracks or joints of furniture close to where you sleep, as these provide perfect hiding spots.

Use your flashlight to check the baseboards or skirting boards along the wall closest to the bed and look behind any picture frames or loose wallpaper.

Persistent infestations may also push bed bugs to travel through wall voids, electrical outlets and sockets, which makes early detection crucial in order to control their rapid expansion throughout your living space.

If you suspect or confirm any of these signs, you must act immediately to prevent the infestation from spreading, which can happen very quickly. Delaying action allows bed bugs to multiply and invade additional areas of your property, making eradication more difficult and costly. Moreover, swift intervention helps reduce the risk of bites and minimises disruption to your daily life.

 Do not move items like clothing, bedding, soft furnishings or furniture out of the room, as this will simply spread the bugs to other areas of your home.

Immediately strip all bedding, clothing, and any soft items in the affected area. Place them in sealed plastic bags and take them directly to the washing machine. Wash at the highest heat setting the fabric allows and dry on high heat for at least 30 minutes to kill all bugs and eggs. Do not reuse the plastic bags.

Use a vacuum with a narrow crevice tool to thoroughly clean the mattress seams, tufts, under the bed, along baseboards, and in and around the bed frame. Immediately dispose of the vacuum bag (or empty the contents of a bagless vacuum) in a sealed plastic bag outside your property.

Purchase bed bug-specific zippered encasements for your mattress and box spring. Leave these on for at least one year. This traps any bugs inside and prevents them from biting you or escaping.

Professional pest control is almost always required for effective eradication. Contact Rentokil Pest Control immediately. Rentokil use specialised treatments (often a combination of heat, steam, and professional-grade insecticides) that are more effective than DIY methods.