What could cause an egg to mold?

I have six eggs incubating in a glad tubberware that are each about 2-3 weeks old. I went to check on them this morning and found one had begun growing mold. I removed it from the rest of the eggs and changed the perlite. Then I took a wet rag and wiped the mold off the egg. I noticed that even after cleaning it off, the egg has a rotten smell to it. It also seems extremely swollen, like if I touched it too roughly it would burst. I almost positive that this egg has "expired." None of the other eggs seem affected by this egg, but I'm worried that the others will grow mold now too. What could cause this? I'm incubating them in a gladware with 1:3/4 cup ratio of perilite to water. They are not in an incubator, but in a drawer under my Leo's tank which stays a constant 82 degrees from the UTH. I just can't figure out what I'm doing wrong. Am I using too much water? The tubberware is air tight, should there be a few small holes in it for air circulation? Would an incubator work better, even though the eggs are always at 82-83 degrees? What should I do to prevent this from happening to the rest of my eggs? Any info or support would be much appreciated!

mold could have been caused by,

No air
high humidity
to moist

are you using albeys incubation method? if not. do you have a scale?

there should at least be about 4-6 airholes, and the humidity should be in the 80's,

go to albeys website Albeysreptiles.com and read the "how to incubate' page

also, if you dont have one already, but a didgital thermometer with a probe, and masure both humidity amd temps in the container te eggs are in

Originally Posted by Niqui13

I have six eggs incubating in a glad tubberware that are each about 2-3 weeks old. I went to check on them this morning and found one had begun growing mold. I removed it from the rest of the eggs and changed the perlite. Then I took a wet rag and wiped the mold off the egg. I noticed that even after cleaning it off, the egg has a rotten smell to it. It also seems extremely swollen, like if I touched it too roughly it would burst. I almost positive that this egg has "expired." None of the other eggs seem affected by this egg, but I'm worried that the others will grow mold now too. What could cause this? I'm incubating them in a gladware with 1:3/4 cup ratio of perilite to water. They are not in an incubator, but in a drawer under my Leo's tank which stays a constant 82 degrees from the UTH. I just can't figure out what I'm doing wrong. Am I using too much water? The tubberware is air tight, should there be a few small holes in it for air circulation? Would an incubator work better, even though the eggs are always at 82-83 degrees? What should I do to prevent this from happening to the rest of my eggs? Any info or support would be much appreciated!

Infertile eggs almost always mold, so it may have been infertile. Use some denesex foot powder and sprinkle it on the egg, that will kill the mold but if it has a foul odor that usually means it was infertile.

Mold on fertile eggs is often caused by too high humidity and not enough air in the egg conatainer. I use 4 small holes in each lid, 2 of opposite sides with the smallest drill bit I could use. I also open the egg container 1 time a week to allow fresh air to get in the entire container.

You're probably not doing anything wrong. If one egg gets massively moldy alongside a bunch of others that are fine, then that one was almost for certain infertile. (and now rotten too) You did the right thing by removing it from the good eggs as soon as you spotted it. Watch the others closely for signs of mold, and if you see any signs, you need to adjust your humidity down and your air ventilation up. Otherwise you are fine. Even if your conditions are perfect for fertile eggs, an infertile egg will still mold up like crazy.

I have to agree with it being infertile.... At least the others are fine!

I did not have any holes in my tupperware container, so I made a few. It might have been due to insufficient airflow. I also checked the humidity after making the holes. It was about 78%. Does that sound right? Also, the molded egg was fertile at one point, I'm sure of it. There were veins growing inside the egg, with a red oval near the center.(Looks a little bit like a bullseye.) I did have to get rid of it sadly. The smell was too strong to be coming from a live egg. I opened the egg, and I was right the insides were black.(I like science and was interested to see if I could figure out what went wrong.) It smelt like a stink bomb when I opened it. I did see an embryo, though, about the size of a bean. What would make a fertile egg mold? If there was something "genetically" wrong with the embryo and it died, would the egg start to mold? I don't really believe it was something I did, because all my other eggs are fine and they have all been inbubating with the same heat and humidity. I could be wrong, though. I'm just trying to learn from my mistakes. What does everyone else think, I could use some advice? Thanks

Originally Posted by Niqui13

I did see an embryo, though, about the size of a bean. What would make a fertile egg mold? If there was something "genetically" wrong with the embryo and it died, would the egg start to mold?

Sorry, yes I forgot about that possibility. That is most likely what happened. It was fertile but it died. This does happen sometimes and as long as there's nothing wrong with your incubation methods (which it really sounds like there's not) then it is a good thing that it died because there was something not right about it. "genetically" wrong, like you said. And once an egg/embryo is dead, the natural immune system that a fertile living egg has, stops. And the egg quickly goes bad.

Still the same advice re the other eggs. Watch them closely for signs of mold but if all the other eggs stay fine then that egg was just destined to die It happens. nature sux sometimes.

Ive had that happen to a couple of fertile eggs, they just don't progress and develop so they die out.

What your doing sounds very good, so I would agree that there was just osemthing not right about that baby and it failed to develop.

If you get mold on fertile eggs, use a little desenex foot powder to kill the mold, unless they have "died" they may still hatch.