Give scientific reasons: Cockroaches are harmful to human life.

(N/A) $1$. Many species of cockroaches are wild and have no economic importance,but a few species thrive in and around human habitats.
$2$. They are considered pests because they destroy food and contaminate it with their smelly excreta.
$3$. They act as vectors for various diseases by carrying pathogens on their bodies and contaminating food and water,which can transmit bacterial diseases to humans.