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Why Roaches Come Out At Night

kitchen at night

You may have heard that cockroaches are nocturnal, but have you ever wondered why? As it turns out, they have specific activity rhythms where they tend to be inactive during the day and start to hunt for food at night. This usually happens around 4 hours after the lights go out. They emerge to feed on whatever they can find in your house including food that's been left out, pet food in a dish, crumbs on the floor, garbage, sludge between the stove and counter, or any other source of fresh or rotting food matter.

Do they come out in the day? Yes. But, if you are seeing cockroaches during the day, it is a good indication that you have a significant infestation. Daytime activity usually means that food sources are limited for the population of cockroaches present, and those roaches are forced to hunt for a meal at less than ideal times.


When cockroaches get into a home they can cause problems day and night. Here are a few of the problems you can expect:

  • Roaches can possibly be carrying the eggs of parasitic worms which can lead to problems with dermatological symptoms and respiratory issues.
  • Roaches are connected to asthma. There have been studies that indicate that there is an increase in asthma symptoms in homes where there are cockroaches present. When roaches leave their droppings, shed parts, and saliva, these can trigger a reaction. This can be made worse if those bugs invade ventilation systems because, when the air turns on, particles can become airborne.
  • Roaches have been linked to stomach illness. They crawl through sewers and dumpsters and then squeeze into your home to deposit harmful bacteria onto food preparation surfaces, shelves, silverware drawers, and more. Anywhere bacteria can be found, cockroaches are right at home.
  • Roaches are also linked to diseases. According to the World Health Organization, cockroaches are proven to (or suspected of) causing cholera, leprosy, plague, dysentery, typhoid fever and viral diseases such as poliomyelitis.
  • Roaches sometimes bite humans. While not common, roaches can, and do, bite people. The most common place for a cockroach bite is on the eyelids since they like to nibble on eyelashes. If bitten by a roach, the reaction is typically a red, swollen area due to the transfer of harmful bacteria to the bite wound.

If you are dealing with roaches in the day or in the night, or you would like to prevent cockroaches from getting into your home in the first place, the professionals here at Rottler Pest & Lawn Solutions are standing by to assist you with industry-leading pest control in St. Louis, Columbia, Wentzville, Springfield, Fenton, and many more locations. For more information, or to schedule service, reach out to us today.

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