Your daughter and her friends should start by documenting the sighting thoroughly. They need to take clear photos or video of the cockroach itself, and look for additional evidence such as droppings, shed skins, or egg cases, since this documentation will be essential if they need to file a complaint or request a refund [1][2]. They should keep all communication with the host within the Airbnb messaging system to create an official record.

Next, they should message the host calmly and factually, describing when and where they saw the cockroach and asking how the host plans to address it—whether through pest control service, inspection, relocation to another unit, or a refund [1][2][3]. The distinction between a single roach and an active infestation matters: one isolated sighting does not automatically signal a broader pest problem, but multiple roaches, repeated sightings, or visible droppings indicate a more serious issue that warrants immediate escalation [2][4][5].

While waiting for the host's response, they should reduce conditions that attract cockroaches by sealing all food in airtight containers or refrigerating it, avoiding leaving dishes in the sink, emptying trash frequently, and keeping kitchen and bathroom areas dry [1][2][6]. They should also check their luggage, clothing, and bags before packing to prevent accidentally transporting roaches home [1][2].

If the host is unresponsive or unhelpful, or if they observe signs of a genuine infestation, they should contact Airbnb support directly with their photos and a factual description [1][2]. Airbnb's ReBook and Refund Policy covers cleanliness and safety issues, and the platform may offer alternative accommodations or a refund if the property is deemed uninhabitable [1]. They should avoid spraying chemicals without the host's approval, as this can create safety issues and complicate any formal complaint [1][3][4].