A hygrometer measures humidity.
I've read and reread your original post and put it together with what you've said since. You had three clutches that did fine (if you don't count the food issue), then you started having problems. If they're hatching on time and a majority are hatching fine, drying off and fluffing fine, walking around, eating, drinking, THEN dying... I'd say nothing wrong with the incubator. Temp and humidity must be fine. Luv, I really think your mum is right. You really need to wash and sanitize the incubator. After it's dry, let it sit for several months before putting another clutch in it. Here's a thread on sanitizing incubators. There are loads more where this came from... https://www.backyardchickens.com/t/93671/cleaning-the-incubator-pics
I've read and reread your original post and put it together with what you've said since. You had three clutches that did fine (if you don't count the food issue), then you started having problems. If they're hatching on time and a majority are hatching fine, drying off and fluffing fine, walking around, eating, drinking, THEN dying... I'd say nothing wrong with the incubator. Temp and humidity must be fine. Luv, I really think your mum is right. You really need to wash and sanitize the incubator. After it's dry, let it sit for several months before putting another clutch in it. Here's a thread on sanitizing incubators. There are loads more where this came from... https://www.backyardchickens.com/t/93671/cleaning-the-incubator-pics
