Reappearance of Odor in Home
Last summer (around this same time in June) we started to smell an odor. We rarely smelled it in the morning. It was strongest at night and early morning (before dawn) and was non-existant in the daytime. And it orginated on one side of our house. We have a two family and the smell was strongest in the first floor (where our tenants live) by the meter. But it also came up fairly strong to our second floor portion through an outlet. The smell lasted last year from June to around November and our home inspector concluded that it was a dead rotting rodent (he didn't find the rodent, but said the smell was typical) probably in the wall. He recommended to just ignore it and as soon as the rodent decompsed, the smell would be gone. Since we didn't smell it after November, we thought that's what happened.
However, to our horror, the smell is back! It just started again about 2 weeks ago and follows the same pattern - originates on the same side of the house and appears around the same timings.
Any ideas what it could be? Could it have anything to do with our central air? Although, there is no smell in the attic where the unit is housed and it smells whether the central air is on or not. It's not a gas leak because last summer we had PSE&G over several times to confirm and reconfirm. What is it? Could it coincidentally be another dead rodent in the wall? I find that hard to believe just because if it's a dead rodent, shouldn't the smell be more permanent rather than having such specific timings (the smell comes only late at night.)? Any thoughts?