Take photos or videos of the problem and contact your host right away. Your host is required to fix these issues, and they'll likely need to hire a cleaning service or pest control company. Sometimes these problems can be fixed within a few days.
If your host doesn't take action or the problem isn't fixed, you may move out earlier than the end of the contract period. Once you've worked things out with your host, let us know so we can update your lease agreement details.