Cockroaches are commonly found pests in our home.There are 4600 total species of cockroaches worldwide of which 30 associated with human habitat.About four species are well-known pests.
Cockroaches have broad, flat bodies and relatively small heads. They are generalised pests, with few only modifications, and may be among the most straightforward living insects. The cockroaches have their mouthparts on the underneath of the head and include generalised chewing mandibles. They have big compound eyes, two ocelli, and long, adjustable antennae.
Cockroaches are commonly found in homes and buildings because they prefer warm conditions close to food and water. Unfortunately, cockroaches can create allergies and trigger asthma attacks, especially in children. They can also spread nearly 33 different kinds of bacteria.
Cockroaches are mainly night-loving and will run away when exposed to light. Cockroaches leave chemical traces in their faeces, as well as emitting airborne pheromones for mating and swarming. These chemical traces transmit bacteria onto the area. Others will follow these paths to discover sources of water and food, and also find where other cockroaches are living. Thus, cockroaches can exhibit rising behaviour, in which group or swarm behaviour arises from a simple set of individual cooperation.
Cockroaches are among the most robust insects. Some species are capable of remaining alive for a month without food and can survive with limited supplies, such as the glue from the back of postage stamps. Some can go without air for 45 minutes.
A cockroach has three stages throughout its life cycle: egg, nymph, and adult. Adults lay eggs held within egg cases that are dark-coloured and about the same size and appearance as a dry kidney bean. Eggs prepare into young ones called nymphs. In a typical cockroach group, nymphs are more various than adults.
Some of the best-known cockroaches are
The American cockroach (Periplaneta Americana) about 30 mm (1.2 in) in length;
The German cockroach (Blattellagermanica) about 15 mm (0.59 in) in length;
The Asian cockroach (Blattella Asahi Nai) also about 15 mm (0.59 in) long;
The Oriental cockroach, Blatta Orientalis, about 25 mm (0.98 in).