Roaches are nearly invincible. But, how long can a cockroach live without food or water? With so many myths, we compiled this set of studies and data. Understanding their limitations will help prevent roaches from taking up residence in your house.
Roaches vs No Food or Water
- How long can a cockroach live without food? With water and no food, most roaches can live up to one month.
- How long can a roach live without water? With no water, most roaches will die within one week.
- How long can a cockroach live without food and water? Without food or water, most roaches will live just one week.
There are many variables to these answers. There are 4,600 cockroach species, of varying sizes. Sex, temperature, and humidity also play a role in their survivability.
Because of these variables, the lifespan without food or water is actually a range, not a specific number of days.
For more detail on each variable, see each section below.
How Long Can Cockroaches Live Without Food and Water?
Cockroaches can survive from 4.8 to 50 days without food or water, according to a 1959 study performed by the Army Quartermaster Corps.
- Results: Female cockroaches lived longer than males. And larger species lasted longer than smaller ones. The most resilient individual was the female German cockroach, surviving 50 days without food or water. The variables included sex, species, and humidity.
- Results: Humidity also affected lifespan. Higher humidity resulted in longer life, with humidity of 50% to 100% being the most favorable condition. In the test a controled humidity between 36 – 40% resulted in all species living one month without food.
The above results were published in this October 1959 study: The Effect of Radiation on the Longevity of the Cockroach, Periplaneta americana, as Affected by Dose, Age, Sex and Food Intake. ~ Source
How Long Can a Roach Live Without Food?
A cockroach’s lifespan without food is one month. When food is scarce, cockroaches slow down and focus on survival. The ambient temperature drives their biological functions, so they’re more active when it’s hot.
They become more active while using less energy. These insects hibernate in winter to conserve energy, especially if food is scarce.
Roaches are cold-blooded, meaning they can control their energy demands by lowering or increasing their body temperatures. When starving, these insects can lower their body temperatures, which in turn reduces the amount of energy they use.
This process helps cockroaches to survive for longer without food.
How Long Can a Roach Live Without Water?
A cockroach can only survive about one week without water. Cockroaches are susceptible to dehydration and typically can’t go more than one week without water. A few days without water can render a roach too slow to move.
Without water, cockroaches lose weight, and their cells die at a greater rate. Mitosis, or cell division, decreases by as much as 50% when a roach is starved of food and water.
Will Cockroaches Leave the House if There is No Food?
Cockroaches don’t necessarily leave a house without food. Whether these pests remain is dependent on the presence of other food sources.
This type of insect feeds on everything it can digest. Some of their favorite food items are human hair, cellulose-based paints, paper, cardboard, and wallpaper. Female roaches will even eat their own eggs.
Roaches are dreaded household/commercial pests because of their voracious appetites and propensity to scavenge for food. Insects like these have a remarkable ability to survive without food for long periods.
They’ll eat just about anything and hang around your house even if there’s nothing to eat.
Other survival methods, including cannibalism, help them avoid starvation.
Will Cockroaches Live in an Empty House?
Cockroaches are adaptable insects that swiftly settle into an empty home and establish a new colony.
These insects can eat organic stuff, including sweet, starchy, and meaty foods. Paper, cardboard, and wallpaper paste are also food for cockroaches. Unless the food source is entirely exhausted, roaches will not depart an empty residence.
These insects feast on the nymphs or dead and dying roaches they find to avoid starvation. If pushed to the absolute limit, starving cockroaches will eat their droppings.
If a roach colony leaves your house, it’s more probable they’ll expand their food hunt and use your abandoned home as a base for warmth and refuge. Foraging for food and water, they will scavenge your neighbors’ backyard and trash cans.
Most cockroach species live in areas with high humidity, meaning they have a steady water source.
The only way to ensure that the roaches do not reappear is to take action to eliminate them.
How Can a Cockroach Survive When Trapped?
Cockroaches have a unique breathing system that allows them to survive. They can go without air for long periods. A cockroach can live for up to 3-5 days if kept in a sealed plastic bag.
Cockroaches have a unique respiratory mechanism that allows them to thrive on very little oxygen. Fridge seals do not prevent cockroaches from dying of dehydration. It will be challenging to submerge them.
This is because cockroaches have a distinct mechanism of breathing. As a result, they are better at utilizing oxygen. They need less air to survive because of their small size and can hold their breath for up to 45 minutes.
Cockroaches can even survive without their head.
How Can I Get Rid of Roaches at Home?
According to the National Pest Management Association, you can keep cockroaches at bay by cleaning your kitchen daily and keeping food sealed. Disposing of garbage regularly and tightly sealing unused containers might help prevent roach infestation in your home.
To keep pests out, homeowners should look for and cover any holes or crevices in their houses, particularly those for utilities and pipes. Additional precautions should be taken to ensure basements and crawl areas are well insulated and dry.
Some homeowners have had success repelling roaches with essential oils, especially peppermint oil.
Extreme temperatures can kill roaches and their eggs.
They have survived for millions of years and have an average life span of 20-30 weeks under normal conditions. Cockroaches can withstand extremes in their environment because they can regulate their internal temperature, survive a lack of water, and consume rotten foods.
Learn more about roaches in our huge Cockroach Guide.
How long can a roach live without food? It is incredible how long cockroaches can live without food and water.
These insects can survive without food for up to a month and water for up to a week. They mostly switch to survival mode when starving. During this period, they rely on their cold-blooded nature to stay alive. Roaches will lower their body temperatures, reducing the energy demand.
- About the Author
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Bryan Haines is a co-founder and writer at The Buginator. And is working to make it the best resource for taking back the outdoors from biting, stinging pests.
He also blogs about travel at Storyteller.Travel and photography at Storyteller Tech. Bryan is a partner at Storyteller Media, a publishing company he runs with his wife, Dena.