Bed Bug Identification: Pictures, Signs & How to Spot Them

By Jeffrey Grill | Reviewed by Jeffrey Grill | Updated: December 28, 2025

Quick ID Guide: Is It a Bed Bug?

• 🔍 Visual ID: Adult bed bugs are reddish-brown, flat, oval-shaped, and roughly the size of an apple seed (5-7mm).
• 🥚 The Eggs: Tiny (1mm), pearly white, and often found in clusters in tight crevices (resembling grains of rice).
• 💩 The Signs: Look for fecal stains (dark black dots that bleed like marker ink) and rust-colored blood spots on sheets.
• 📍 Where to Check: 90% of bugs hide within 15 feet of the bed. Inspect mattress seams, box spring corners, and bed frame joints.
• ⚠️ Look-alikes: Often confused with Bat Bugs, Carpet Beetles, or Cockroach Nymphs.

table of contents

• Appearance
• Male vs. Female Bed Bugs
• Pictures on Mattresses and Sheets
• Insects Confused with Bed Bugs
• Bite Pictures
• Expert Identification Services
• Brochures

What Do Bed Bugs Look Like?

Accurate bed bug identification relies on spotting specific physical features. An adult bed bug (Cimex lectularius) is visible to the naked eye. They are flat, wingless insects that are brown in color, turning reddish-brown and swollen after a blood meal.

Size Comparison: Adults are 5-7mm long—roughly the size and shape of an apple seed. Younger bugs, called nymphs, are smaller (1-4mm) and can be translucent or pale yellow until they feed.

See our complete gallery of bed bugs photos.

Male vs. Female Bed Bugs

If you found one male bed bug, the infestation might grow slower, but it usually implies a female is nearby. Female bed bugs have a rounded abdomen, while male bed bugs have a pointed tip. Both have a 3-segment beak and 4-segment antennae.

Pictures of Bed Bugs on Mattresses and Sheets

Pictures of Bed Bugs on Mattresses & Sheets

You will often see the mess they leave behind before you see the bugs themselves. Inspect your sleeping area for these three major clues:

• Fecal Stains: Bed bug droppings appear as black spots or dark, ink-like dots. Unlike dirt, these stains will bleed into the fabric of your sheets and mattress like a marker tip.
• Blood Stains: Small, rust-colored smears on pillowcases are caused by crushing a bug that has fed recently.
• Shed Skins (Casings): As nymphs grow, they molt. Look for hollow, pale yellow skins in mattress seams and crevices.

Insects Confused with Bed Bugs

Common Bed Bug Look-alikes

It is easy to confuse bed bugs with other household insects. Use this guide to tell them apart:

1. Bat Bugs vs. Bed Bugs

Bat bugs are nearly identical to bed bugs but have longer hairs on their thorax (neck area). They are usually found in attics or near bat roosts, whereas bed bugs are found in mattress seams.

2. Carpet Beetles

Carpet Beetles are rounder, and their larvae are fuzzy or hairy. Unlike bed bugs, they do not bite humans but can cause an allergic skin reaction.

3. Cockroach Nymphs

Baby German Cockroaches are cylindrical rather than oval and have two distinct "tail" pipes (cerci) at their rear. They move much faster than bed bugs.

Swallow Bug Compared to Bed bug

Bat Bug Compared to a Bed Bug

Assassin or Kissing bugs

German Cockroaches

Baby or young cockroaches are similar in appearance to bed bugs.  Eggs are rectangular instead of the oval or pear shape found with bedbug eggs.  Insects are closer to brown than red.

Carpet and Warehouse Beetle Adults

Spider Beetles

Other Insects Confused with Bed Bugs

• Tropical bed bugs
• Mexican Chicken/Poultry bugs
• Earwig
• Fleas
• Stink bugs
• Wheel bugs
• Ants
  

Bed Bug Bite Images & Symptoms

Bed bug bites often appear in a straight row or zigzag pattern. They can appear immediately or take up to 14 days to show. While bites are a sign, they are not definitive proof without finding the bug or fecal stains.

Photo of Immediate Reaction to Bed Bug Bite

Mild skin reactions will heal in 2 to 3 days.  Bites result in skin itch which can be treated with an over the counter topical such as Aveeno or a product made specifically for bed bug bite itch.

30 Minute Bed Bug Bite Reaction

Symptoms 48 Hours After Bed Bug Bite

Bed Bug Bite Compared to Scabies

Bed bug bites and scabies identification are often confused.  Read more about causes of body itch.

How to Confirm an Infestation

If you cannot identify the bug capture it on a piece of clear tape and stick it to a white index card. You can:

• Bring it to your local Cooperative Extension
• Send the sample to the Cornell Diagnostic Laboratory (or your local University). 
• Call a professional exterminator for an inspection (1-877-673-2704 - in the U.S. for a referral)

Brochures

Each of these free brochures provide additional information on bed bug identification and treatment. (click on title to download each bed bug identification brochure).

Ask a question or share your experience

references

University of Nebraska Department of Entomology