What is this secretion coming out of my duck egg?

[Run Amock DucksNChickens]

I've got duck eggs going into lock down tomorrow and I found this! I took it out in case it exploded. What is it? What causes this?

 

[Bigtom Turkey]

In shipped eggs these thing happen. I don't know what it is but I do know it (and really any other problem you can think of) happens in shipped eggs.

 

[MysteryChicken]

I've got duck eggs going into lock down tomorrow and I found this! I took it out in case it exploded. What is it? What causes this?View attachment 2884324

Are these shipped eggs, or eggs from your own birds?

 

[Run Amock DucksNChickens]

Thank you for replying.
Yes, we had 14 duck eggs posted to us. 5 infertile and 2 like this. There wasn't any movement and they were developed less than the others. Should I have left them in?
7 left for hatching.

 

[HollowOfWisps]

Never leave an egg in the incubator that is leaking fluid it can cause the bacteria to move to your other eggs. Bacteria->gas->pressure->release is what you're seeing right now.

 

[Run Amock DucksNChickens]

Thank you. I'm glad I took it out.