Ammonia takes the itch out of bites. If you find ants crawling over clean dishes in the cupboard, you may conclude that an imperceptible film of grease remains on the dishes. Make sure that your dishes will not be damaged by the concentration. For cockroaches, spraying can be effective. Concentrate especially on crevices in wood where eggs tend to be deposited.
Cockroaches live in the soil under the houses, around water and sewage pipes, in cesspools, etc.
They migrate into the house searching for food or shelter. They eat clothing, books, and furniture, as well as food, voraciously. They do not only crawl, they fly as well. A mixture of mashed potatoes and boric acid is lethal to cockroaches but this is a dangerous poison and must be kept far from the reach of children and pets. Cockroaches especially like to build their homes in the subterranean areas of bathrooms.