Affect is a psychological term for an observable expression of emotion. A person's affect is the expression of emotion or feelings displayed to others through facial expressions, hand gestures, voice tone, and other emotional signs such as laughter or tears. Individual affect fluctuates according to emotional state.
There are over 3,000 different species of cockroaches-some are considered pests while others are beneficial in their natural environment. The three main types of cockroaches commonly found in homes in South Africa include the German cockroach, Oriental cockroach and American cockroach.
Cockroaches are insects of the order Blattodea, sometimes called Blattaria, of which about 30 species out of 4,600 total are associated with human habitats. About four species are well known as pests.