Maybe because I have a super sensitive pregnant nose, but when they first hatch... no problem, by the end of the hatch WOW! But my hatches go a couple days... I think it's from the goop getting into the water on the bottom and festering at 100 degrees if you know what I mean!
The first hatch I did was with a brand new bator so I don't think it's from not being clean, but I washed it out several times with antibacterial dawn... I was leary of using bleach, I used bleach to clean the area that the bator was cleaned in though.
Oh well... I'm bracing myself for another stink fest in a few days! Don't get me wrong, I wouldn't trade that in for anything because that stink means MY BABIES ARE HATCHING!
I guess it is a smell only a mother could love/tolerate LOL!
Oh and my bator is in the living room... and because I have to put my ear right to the bator to hear if anyone is peeping I get the whiffs!