1. Bedbugs
Improving health worldwide

2. What are bedbugs? Bedbugs are small insects They come out at night
They are ectoparasites
Adults are red-brown in colour
They are about the size of an apple pip or red lentil
Male, female and baby bedbugs all suck blood
They are flat as pancakes when hungry

3. What is an ectoparasite?
An ectoparasite is an organism that feeds and often lives on the surface of another organism – called the ‘host’
It depends on the host for its survival but usually causes harm to the host by its behaviour.
Examples of ectoparasites include:
Ticks
Fleas
Head lice

4. What do they look like? Antenna – bedbugs have 2 long antennae for
sensing.
Proboscis for feeding is folded under the head.
Eyes – bedbugs have good vision
Legs – Bedbugs have 6 legs, each ends in a claw. They are good walkers but cannot climb smooth surfaces.
Wing pad – bedbugs have evolved from winged insects, they cannot fly.
Thorax has 3 segments where the legs are attached.
Abdomen – the segments can stretch apart as the bug fills with blood.
Males have pointed bottoms.

5. Lifecycle takes about 2 months to complete.
Bedbug lifecycle
All bedbugs feed on blood but adult females will use some of the blood they take to make eggs. Females will lay around 150 eggs in their lifetime.
Eggs are white, curved and 1mm long. They have a lid that pops off when the babies hatch. Eggs are laid in cracks and crevices.
A baby bedbug is called a nymph and is about the size of a pin-head.
When nymphs hatch they are almost transparent, but later becomes light yellow/beige.
A nymph sheds its skin five times between egg and adult, getting darker and larger each time.
Lifecycle takes about 2 months to complete.

8. Where do they live? Bedbugs like to live where people sleep
They are most often found in the bedroom
They can be in the bed frame and in the bedding
They will hide in any cracks and crevices, furniture or light fittings.

9. How do bedbugs arrive? On second-hand furniture On luggage
In old clothes and fabrics
Bedbugs can be found in all sorts of places. In luxury hotels, in hostels, in hospitals, on aeroplanes and in houses.

10. Bedbug facts Adult bedbugs can live for up to 4 years
Adult bedbugs can survive for up to 1 year without blood
Nymphs can survive for up to 4 months without blood
Bedbugs like to live in groups and will emit a distinctive
odour to encourage other bugs to join them.
Bedbugs bite at night, using their proboscis.
Bedbugs feed for 3-10 minutes.
Allergic reactions are very common.
Bedbugs can be found clean houses
and in luxury hotels.
There is no evidence that bedbugs
carry diseases.

11. Bedbug bites Bedbugs unfold their proboscis when they feed.
They will often take a number of small feeds in a row.
The bedbug doesn’t want to wake you up so it has special chemicals to numb the bite.
Reactions to bites develop very quickly, in about 30 minutes.
Raised red, itchy lumps appear on the skin.
These can be very irritating.
Photo credit: Aaron Edwards/Flickr

12. What to look for?
Look for signs and symptoms of bedbugs around the bedroom:
Live bedbugs and eggs hidden away
Black spots of bug poo on mattresses and furniture
Red spots of blood on bed sheets from squashed bugs
Shed skins of bugs around their hiding places
An unpleasant, musty odour.

13. What can be done? Call in the local council/pest control companies!
They may recommend:
Stripping beds and dismantling furniture.
Vacuuming all over the bedroom and in cupboards, empty the vacuum cleaner into a sealed plastic bag.
Washing bedding and clothes at a high heat (60◦C) and tumble-drying at high heat for at least 30 mins.
Putting clothing into the freezer for 48 hours.
Throwing away heavily-infested mattresses, beds and other furniture.
They may also suggest:
Using strong insecticides to kill bugs but this has to be done by a professional.

14. What do you remember?
Take the bedbug quiz!

16. Teacher’s notes and Links

17. Credits:
Project Coordinator: Vickie Bazalgette, London School of Hygiene & Tropical Medicine
Scientific Advisor: Cheryl Whitehorn, London School of Hygiene & Tropical Medicine
Educational Advisor: Nan Davies, Thames Ditton Junior School
Designer: Andrew Forkes
Full bedbug lesson plan can be found at