that the chemical would last 30 days and when I was still getting bites, he came to inspect the apartment again did not find any bugs so he suggested that I had allergies. They looked at the other apartments surrounding didn't find any so decided they wouldn't spray again (even though I was still getting bites). I bought the chemical and sprayed twice myself with in 14 days they are still here and even though I'm keeping my clothes tied up in garbage bags and heat treating them regularily (which is ruining my clothes) I'm having no luck. The landlords did mention that another tenant in one of the other suits had them last summer but they sprayed and assumed they were gone.