Cockroaches are notorious for their ability to survive in harsh environments. They can hold their breath for up to 40 minutes and survive being submerged in water for half an hour or longer. But just how long does it actually take to successfully drown a cockroach?
Can cockroaches breathe underwater?
Cockroaches cannot breathe underwater like fish can. They do not have gills or any specialized breathing apparatus for extracting oxygen from water.
However, cockroaches can hold their breath for extremely long periods of time. They are able to do this thanks to special adaptations in their respiratory system and body chemistry.
Cockroaches breathe through spiracles, small holes connecting to an internal respiratory system of tubes and air sacs. Prior to submersion, they are able to tightly close their spiracles, preventing water from entering the respiratory system.
Cockroaches also have an extremely slow metabolic rate. Their resting metabolic rate is only about 75% of other insects of similar size. This means they use up oxygen much more slowly.
They are also able to greatly reduce their oxygen requirements by lowering their metabolic rate even further while holding their breath. This allows them to survive for up to 40 minutes without taking a breath in normal conditions.
How long can cockroaches hold their breath?
The exact length of time a cockroach can hold its breath depends on the species and environmental conditions:
- American cockroaches can hold their breath for up to 40 minutes at rest.
- German cockroaches can hold their breath for up to 30 minutes at rest.
- Oriental cockroaches can hold their breath for about 45 minutes at rest.
Under conditions of physical exertion or higher temperatures, this time is reduced significantly. But generally, most common household cockroaches can easily hold their breath for 15 minutes or longer.
How do cockroaches survive underwater?
Cockroaches are able to survive underwater for extended periods of time due to three key adaptations:
- Holding their breath – Closing spiracles tightly to prevent water entry while lowering metabolic rate to reduce oxygen needs.
- Trapped air – Air trapped between their body and wing cases further slows water penetration.
- Slow water penetration – Their waxy, hydrophobic cuticle prevents rapid water absorption into the body.
These adaptations allow cockroaches to effectively “breathe” the oxygen already present in their bodies while underwater. Trapped air pockets create a temporary physical gill, allowing for gas exchange with surrounding water.
Does water temperature affect drowning time?
Yes, water temperature plays a significant role in how long a submerged cockroach can survive before drowning.
Warmer water temperatures cause cockroaches to metabolize their oxygen stores faster. Colder water temperatures slow down their metabolism, allowing them to survive underwater for longer.
A cockroach submerged in 50°F (10°C) water can survive nearly twice as long as one in 95°F (35°C) water. This effect is due to the temperature dependence of metabolic rates in insects.
In one experiment, German cockroaches were able to survive underwater:
- 95°F (35°C) water – 16 minutes
- 77°F (25°C) water – 25 minutes
- 50°F (10°C) water – 41 minutes
So colder water makes it take significantly longer for a submerged cockroach to drown.
How do you successfully drown a cockroach?
To ensure successful drowning of a cockroach in a reasonable time period, here are some key tips:
- Use warm or hot water – 93-104°F (34-40°C) is optimal.
- Agitate the water to prevent air pockets forming.
- Add a drop of soap to reduce water surface tension.
- Submerge cockroach for at least 45 minutes for most species.
- Ensure the container is escape proof.
The goal is to maximize water penetration into the respiratory system and speed up oxygen use. Experimentally, most cockroaches drowned within 20-30 minutes using warm, agitated water with soap added.
What is the average drowning time?
Under ideal laboratory drowning conditions using warm, agitated water, the average drowning times for common household cockroaches are:
| Cockroach Species | Average Drowning Time |
|---|---|
| German Cockroach | 23 minutes |
| American Cockroach | 27 minutes |
| Oriental Cockroach | 32 minutes |
| Brownbanded Cockroach | 18 minutes |
So most common household cockroaches can be successfully drowned in 20-30 minutes under ideal conditions.
Can drowned cockroaches come back to life?
No, once successfully drowned, cockroaches do not come back to life. Drowning leads to irreversible damage and death.
Underwater, cockroaches rapidly lose bodily function once they have depleted their oxygen stores. Important organs like the brain and heart begin to fail once oxygen levels become critically low.
By the end of the average drowning time, the damage is too severe for the cockroach to ever recover. Even if removed from the water, the cockroach will be dead.
However, it is important to leave submerged cockroaches for at least an hour to ensure death. If the drowning time was insufficient, they may still recover if removed prematurely.
Signs of successful drowning
Once removed from the water, a successfully drowned cockroach will display:
- Lack of movement and complete stillness
- No response to stimuli
- Rigor mortis in the legs and antennae
- Discoloration and opaqueness in body
These are clear signs the cockroach has died and will not resuscitate. If signs of life remain, submersion time was likely insufficient.
Conclusion
Cockroaches can survive underwater for impressively long periods by closing their spiracles, reducing metabolism, and utilizing trapped air pockets. However, they cannot breathe underwater and will eventually drown.
Most cockroaches drown within 20-30 minutes when submerged in warm, agitated water. Colder water extends this time considerably. Once drowned, cockroaches do not resuscitate.
To quickly and humanely drown cockroaches, use warm water with soap added and agitate for at least 45 minutes before disposal. This will ensure a lethal drowning time in most cases.