There are rather more than Four thousand species of cockroach, with Thirty of those species linked with human habitations, and four said to be pests.
Common sorts of pest cockroach are the american, German, Asian and Oriental species. The cockroach belongs to the order ‘Blatteria ‘, and is a traditional insect – cockroach-like species have been on the Earth for over 295 million years.
Cockroaches have a tendency to have flat bodies and small heads. They’re known as generalized insects, with few categorical adaptations, and in reality are quite primitive. Physically troublesome, they have 4 wings, with the top 2 acting as a shield for the more fragile lower pair. They also have compound eyes, and flexible antennae.
A cockroach’s lethal dose of radiation might be as much as Fifteen times higher than ours ( although this isn’t much bigger than that of any other insect ). This is because the consequences of radiation are far worse during cell-division, and cockroach cells divide comparatively rarely, when it changes its skin ( once every week, at most, for minors ). Human cells are constantly changing and dividing, making us more at the mercy of radiation.
Cockroaches are indeed very hard insects. They may be able to survive on little food for up to a month, and need little in the way of nourishment. They’re also able to go without air for extended periods, and some experiments have seen cockroaches recover, after spending as long as 30 minutes submerged in water. These facts may explain why the roach is sometimes called indestructible.
In terms of behaviour, the cockroach displays a mix of competitive and co-operative dispositions. Individuals will leave smell trails to steer others to nutrition or shelter, and swarms of cockroaches have been observed to show group decision-making talents.
Where resources like shelter are limited, they are known to control the situation dependent on their numbers – splitting a group between different shelters, so as to accommodate all members, for example.