Ducklings on day 29 and still no pip----When should I help?

[Panicky]

I have an incubator full of 30-ish ducklings that are on day 29 now. I still haven't seen a single pip yet. I mainly hatch guinea fowl instead of ducks (I've only hatched out ducks once before), and I'm slightly worried now that they haven't come yet. When I candle them they wiggle around everything but there is not a single pip. The temperature has been at around 99.5 F but since its so humid outside and I have so many eggs in the incubator they really haven't gotten any humidity from me. Is there a chance that they are just late bloomers or is the humidity too low for them? When should I help them out?

 

[Isaac 0]

How is your hatch going?

 

[Panicky]

Five have started to hatch, one is out. However, the rest of them have not pipped but clearly still alive. I also now have guinea eggs in the incubator who are a day late

 

[Isaac 0]

Have they externally or internally pipped, if so for how long?

 

[Panicky]

It looks like they've internally pipped last night l for the majority. Some have not yet

 

[Isaac 0]

If they don't externally pip by this afternoon, I would probably put a safety hole in.