Cockroaches are thin, torpedo-shaped insects. Their body shape allows them to squeeze into small cracks or holes in walls and ceilings or dart into drains, thus avoiding all dangers. their outer shell is extremely hard, making them almost imposibble to crush. Cocroaches have sticky pads on their claws upside down ceilings. They also have two little tails called ” cerci” to alert them to danger. These cerci are covered with tiny hairs that, like antennae, are sensitive to things as small as speck of dust or as seemingly innocent as puff of air. If they can not find food, they can sustain themselves for up to a month wiithout food, as long as they have water.
Cockroaches give credence to the old adage that there is safety in numbers. They reproduce at a truly amazing rate. About two months after mating, a new generation of cockroaches is born. One cockroach can produce about two dozen offspring each time it makes. Approximately three weeks after mating the females lay their eggs, which hatch some forty-five days later.
They are the only creatures that can survive a nuclear explosion.
Cockroaches have survived in even the most hostile environments because they possess several unique physical features, an amazing reproductive process, and an immune system that has frustrated even the best efforts of exterminators to get rid of them.
Today there are 3, 500 different species of cockroaches. About four species are well known as pests. They have survived on this planet since the time of the dinosaurs some 350 million years ago.
The name “cockroach” comes from the Spanish word for cockroach, cucaracha, transformed by English folk etymology into “cock” and “roach”. The scientific name derives from the Latinized Greek name for the insect.
Cockroaches live in a wide range of environments around the world. Pest species adapt readily to a variety of environments, but prefer warm conditions found within buildings. Many tropical species prefer even warmer environments and do not fare well in the average household.
Cockroaches are mainly nocturnal and will run away when exposed to light. A peculiar exception is the Asian cockroach, which is attracted to light.
The spines on the legs were earlier considered to be sensory, but observations of their locomotion on sand and wire meshes have demonstrated they help in locomotion on difficult terrain. The structures have been used as inspiration for robotic legs.
Cockroaches leave chemical trails in their feces, as well as emitting airborne pheromones for swarming and mating. These chemical trails transmit bacteria onto surfaces. Other cockroaches will follow these trails to discover sources of food and water, and also discover where other cockroaches are hiding. Thus, cockroaches can exhibit emergent behavior, in which group orswarm behavior emerges from a simple set of individual interactions.
Daily rhythms may also be regulated by a complex set of hormonal controls of which only a small subset have been understood. In 2005, the role of one of these proteins, pigment dispersing factor (PDF), was isolated and found to be a key mediator in thecircadian rhythms of the cockroach.
Research has shown group-based decision-making is responsible for complex behaviors such as resource allocation. In a study where 50 cockroaches were placed in a dish with three shelters with a capacity for 40 insects in each, the insects arranged themselves in two shelters with 25 insects in each, leaving the third shelter empty. When the capacity of the shelters was increased to more than 50 insects per shelter, all of the cockroaches arranged themselves in one shelter. Researchers found a balance between cooperation and competition exists in the group decision-making behavior found in cockroaches. The models used in this research can also explain the group dynamics of other insects and animals.
Another study tested the hypothesis that cockroaches use just two pieces of information to decide where to go under those conditions: how dark it is and how many other cockroaches there are. The study created a set of tiny robots that appear to the roaches as other roaches and can thus alter the roaches’ perception of critical mass. The robots were also specially scented so they would be accepted by the real roaches.
Aside from the famous hissing noise, some cockroaches will make a chirping noise.
Cockroaches are one of the most commonly noted household pest insects. They feed on human and pet food and can leave an offensive odor. They can also passively transport microbes on their body surfaces including those that are potentially dangerous to humans, particularly in environments such as hospitals. Cockroaches are linked with allergic reactions in humans. One of the proteins that triggers allergic reactions is tropomyosin. These allergens are also linked with asthma.