Avoid a Pest Disaster After Flooding

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Avoid a Pest Disaster After Flooding

Pest Disaster After Flooding

Pests can be a major problem after a flood. In this article, we talk about how to know when to get professionals in for pest control and which methods are most effective in the aftermath of a flood.

When should you do pest control after a flood?

Itโ€™s important to do pest control after a flood.

The insects and pests that were displaced by the flood will return, and theyโ€™re looking for new areas to infest.

Flooding can also agitate rats, which when agitated are more likely to come into contact with humans.

Pest control measures should be taken as soon as the floodwaters recede.

7 Common pest issues after flooding


One of the worst pest to deal with during a flood is the cockroach. The cockroach can survive on just about any surface, which makes it easy for them to infest homes and businesses.

As millions of cockroach species live in sewers, gutters, or drainpipes, when we get heavy rainfall these places flood.

If a home or business becomes flooded, the cockroach population will grow rapidly because they thrive in water and moist environments.


Heavy rain and flooding offer a food opportunity for spiders as they will follow their prey, this means when it rains, if insects come inside to get away from the rain, the spiders will follow.

Ground spiders, such as funnel web spiders that build burrows and tunnels under the ground and with high levels of rainfall spiders are being washed out of their burrows and into our unsuspecting paths.

Residents in NSW are being warned about an increase in funnel-web spiders.


Rats carry a particular health risk in flooded areas, as their urine contains leptospires which can survive outside the ratโ€™s body for much longer periods in extreme wet weather. These leptospires in the ratsโ€™ urine can cause Weilโ€™s disease.

Hantavirus can be transmitted from rodents to people through food and water that has been contaminated by rodent urine and excrement.

Their droppings and hair can cause people to sneeze, itch and experience other allergic reactions.

Rats are known as strong swimmers and can swim great distances in search of a new home. They can use damaged pipework, plumbing or cracks to enter properties


Snakes can lose their home during a flood and will explore for shelter out of the way of rising water, and food inside houses, storage sheds and other buildings.

Damaged structures have a better probability of attracting snakes due to the various accessible entrances.

Snakes may be found under debris scattered by the flood or in debris.


Flooding and heavy rain can push ants into homes and businesses.

When rainwater flushes through the ground, thousands of ants try to move out of their nest and seek the closest dry ground.

As floodwaters recede, your property may become heavily infested with garden ants.


Subterranean termites need moisture to survive, but in heavy rain and floods to avoid drowning they do not move to higher ground like other pests, they enter an immobile state to conserve oxygen. During this immobile state termites can survive under water for up to 16-30 hours .

Termites can even survive in saturated soil, as long as the water does not flood their tunnels.

Flooding in and around your home causes the damp conditions that attract moisture-loving termites.


As flood waters recede a greater number of mosquitoes is likely to lead to an outbreak of mosquito-borne diseases.

It is a known indisputable fact that mosquitoes need water!

In recent news, warnings have been issued by NSW and Victorian health authorities, over the mosquito-borne disease Japanese encephalitis.

With floods โ€“ come mosquitoes!

What are some signs of pests in your home?

Pest Disaster After Flooding

You might have pests in your home if you see any of the following signs:


  • Webs
  • Egg sacs
  • Excess flying insects.
  • Seeing spiders.


  • Rat Droppings
  • Scratching Noises
  • Footprints (running tracks)
  • Rub Marks
  • Burrows


  • Live insects
  • Ant pathways
  • Ant nest


  • Shedding or moulted skin
  • Weird noises in dark, cramped places
  • Absence of rodents


  • Hollowed wood, with outer shell of wood intact
  • Earthen shelter tubes and mud packing on brickwork in subfloor areas or around home.
  • Flight tubes from the release of alates (winged form of termites)
  • Flight cuts in trees
  • Swarms of alates flying from the colony (usually in Nov/ Dec)
  • Presence of termite castes in trees or workings
  • Noises
  • Presence of mounds or nests in trees.


  • Hearing a high-pitched buzzing sound
  • Mosquito Bites
  • Seeing mosquitoes moving around on ceilings and glass surfaces.

If youโ€™re unfortunate enough to have experienced catastrophic flooding and are in the process of cleaning up remember pests canโ€™t just be swept up with a broom and cleaned away.!

Contact a pest control professional within 24 hours of the flood so they can provide you with critical advice to take care of any potential contamination from pests.

Pest Disaster After Flooding