What is the smell coming from the furnace?

My husband walked into the house yesterday and started sniffing. I thought he was smelling our dinner, which was just about done. I waited for him to tell me how good it smelled, but instead, he wrinkled his nose. He asked what the smell was that was coming from the furnace? I didn’t smell anything, but I had been in the house all day. He said he remembered the smell as a kid and said it smelled like the stink bug his mom had killed one day. The smell was in the house for days. I knew all about stink bugs and how they would make their way into ductwork through small holes and cracks. The heat from the furnace would kill them and they would end up stinking up the entire house. He called the HVAC and made an appointment to get professional ductwork cleaners to the house. He wanted the ductwork cleaned and sanitized. He then called an exterminator. He told them he suspected an infestation of stink bugs and needed them out of the ductwork so it could be cleaned and sanitized. Not only did he remove several hundreds of stink bugs, but he eliminated thousand of stink bug eggs. He couldn’t believe they had spread so far, and they had survived so well inside the ductwork. He said we were lucky they stayed in the ductwork and not gotten in the house. I was now itching and asked him to check the house to make sure they were only in the ductwork. He laughed and said my husband had already asked him to do it.

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