Preventing and Treating Insect Bites

Why do insect bites itch?

Bites itch because your body reacts to the saliva injected by the insect while it is biting you.

Biting insects have a complex mouth structure that varies between species. It can include a needle-like part that pierces the skin and other parts that are serrated and saw through the flesh to find a blood vessel.

They also have a food canal to suck up blood and a canal that injects saliva containing anticoagulant and anaesthetic. The anticoagulant keeps the blood liquid to keep it flowing and the anaesthetic stops you from feeling the bite so you don’t disturb the feeding insect.

The body’s immune system recognises the foreign material injected into the bite and produces histamine as a defence mechanism. This causes localised inflammation and itching.

Fleas

Fleas are wingless insects that are about 3-4mm long when adult. They are very agile and especially good at jumping.

As a ratio of their size, fleas are one of the longest jumpers of any animal. They can quickly spread widely once inside a building.

There are several types of flea that affect humans, pets and animals and are common in the human environment. They tend to prefer a particular animal host, but will still bite to see if the host is suitable before dropping off.

Common animals that can bring fleas into contact with humans include:

• cats
• dogs
• rats
• mice
• foxes
• birds
• rabbits

See descriptions of the various species on the Flea Species page.

Flea bites

Flea bites look a lot like other insect bites, but there are, however, a few key characteristics which separate them apart.

Bed Bugs

You are most likely to pick up bed bugs from a hotel, where they can crawl into luggage and clothing. They can also catch a ride in bedding and furniture and spread through buildings by crawling through holes in walls, such as for electrical wiring, or along pipe work.

Bed bug bites

Bed bugs tend to feed at night but will search for a host at any time if they are starved. They find a host through an array of sensors that can detect warmth, carbon dioxide and body odours.

Bed bugs feed for only 5-10 minutes until they become engorged with blood, if not disturbed and may spend less than 20 minutes on a host. After feeding, they return to their shelter.

How to spot bed bug bites

• Small, flat, raised bumps on skin.
• Several bites tend to appear in a line or row along an exposed area of the skin. This is usually the arm or leg.
• Several groups of bed bug bites around the body could indicate multiple bed bugs feeding.

How to treat bed bug bites

Bed bugs do not carry diseases so the only treatment needed is to stop itching and rarely for inflammation. If the bites develop into very itchy bumps, general products available from a pharmacy to stop itching are suitable. For inflammation it is best to see a doctor who can prescribe the most suitable treatment. Many people do not react to bed bugs bites so do not need any treatment.

How to prevent bed bug bites

If you are worried about bringing back bed bugs from your travels, then follow these steps to prevent bed bugs from entering your home and feeding upon you at night:

• Leave luggage in your garage or bathroom. Bed bugs don’t like tiles or concrete, and it is easier to spot them on a hard surface compared to carpet.
• If you are really worried take off your clothes in the garage or bathroom and place them straight into the wash.
• Wash and dry clothes on the highest possible temperatures. Bed bugs don’t like heat.
• Vacuum your home, and your furniture thoroughly. This will reduce the size of your bed bug problem by eliminating both the adults and the eggs.

Worried about bed bugs in your hotel or dorm? Follow these steps to prevent them from biting your guests:

• Train staff on how to identify bed bugs.
• Ensure thorough checking for bed bugs is part of your room cleaning process.

Arachnids

Arachnids are a separate Class from insects in the classification of the animal kingdom, distinguishable by their eight legs and two body sections: the abdomen and cepahlothorax.

The group is easily distinguished from insects, which have six legs, three body sections (head, thorax and abdomen) and one pair of antennae. They are both in the Arthropod phylum, however, which consists of animals having an exoskeleton.

The arachnids have many members that can be pests of humans: the ticks, mites, scorpions and spiders.

Ticks

There are around 900 species of tick, all of which are parasites that feed on the blood of mammals, birds and less commonly reptiles and amphibians.

Habit

Ticks inhabit areas with long grass or heavy vegetation. They can sense a host by detecting breath, body odours, body heat, moisture and vibrations through a sensory organ in the first pair of legs.

Ticks do not seek a host but lie in wait, climbing up grass or onto the edge of leaves and hold up their front pair of legs to wait for a host to pass and latch onto — a posture called ‘questing’. They then crawl around the host looking for their preferred site to feed from, such as soft skin.

How to prevent tick bites

In areas of known infestation you can take some measures to reduce the chance of tick infestation:

• avoid long grass and vegetation and keep pets from these areas;
• remove vegetation near your property;
• keep away host animals such as squirrels, mice, rats and other rodents, and deer. Deer carry ticks that carry Lyme disease;
• use an insect repellent such as DEET, which will repel ticks also;
• tuck trousers/pants into boots or socks to prevent ticks climbing onto your skin;
• do a daily body check if out in areas with ticks; and
• wear light clothing so that ticks are easy to spot.

Tick removal 

It is important to remove a tick properly so that you do not leave mouth parts behind in the skin, squeeze body fluid into the bite or cause it to regurgitate into the bite, which will increase the chance of infection.

How to remove ticks:

1. Wear gloves or using a cloth or tissue to prevent catching an infection from contact with the tick;
2. Use a pair of fine-tipped tweezers or commercial tick removal tool;
3. Grab the tick as close as possible to the skin, to include the mouth parts if possible;
4. Gently pull the tick straight out until the mouth parts are removed;
5. Wash your hands with soap and water;
6. Clean the bite area with soap and water or an antiseptic; and
7. Seek medical attention if you cannot remove all of the tick from the skin.

Do not:

1. twist the tick — this can break off the mouth parts and leave them in the skin;
2. use any substance, such as alcohol, gels, ointment or petroleum jelly to try and make the tick drop off as this could make the tick regurgitate into the bite and cause infection;
3. use a flame, which could also make the tick regurgitate, carrying diseases into the skin;
4. scratch the bite because this will increase the risk of infection and cause further swelling.

Tick diseases

Ticks can carry a variety of viruses, bacteria and protozoa, including several at the same time, which can make diagnosis and treatment difficult.

• Lyme disease
• Tick borne encephalitis
• Rocky Mountain Spotted Fever
• Ehrlichiosis
• Colorado Tick Fever
• Australian paralysis tick
• Crimean-Congo haemorrhagic fever