While just the look of them alone is off putting, they can foul surfaces and food and are excellent climbers and swimmers. There is nothing as unpalatable as your favourite nibble that has been “nibbled” by a cockroach.
They will leave behind faeces and a chemical trail which contains compounds some people are allergic to. Symptoms of mild allergy can be experienced by people who are co-inhabiting with cockroaches.
Cockroach control can be difficult due to their ability to breed at alarming levels and hide in inaccessible nooks, crannies and crevices.
If you see one cockroach, you can be sure there are more.