My fictional alien species has a lot of characteristics of both mammals and reptiles. But 1 thing they do well is hear. They can not only hear within the human hearing range, but both below and above it. Infrasound is used for long distance communication. The human hearing range is used for average distance communication. And ultrasound is used for communication between a mom and her babies.
They typically ovulate anywhere from 5-15 eggs. These eggs if not fertilized are just reabsorbed. If they are fertilized, they implant. But the placenta is within the amniotic sac so you have lots of villi going in between cells of the amniotic sack. Once implanted, calcification starts. The amniotic sack along with the baby alien within it grows. Once the calcification has reached the villi, those villi start breaking off and the placenta starts to become a source of protein for the growing baby. This whole process of calcification lasts 2 weeks after which the mother alien goes into labor. It is very painful and depending on the number of babies within that egg shell(yes, sometimes multiple amniotic sacks end up in 1 shell), it can take anywhere from 5 hours to push out a singleton egg to twice that to push out a triplet egg. There is about a 20 minute break between eggs. This means that a twin egg would take ((10+5)/2) = 7.5 hours to push out because the average of 3 and 1 is 2.
All this means it can take anywhere from 1 day, 2 hours, and 20 minutes to 3 days, 7 hours, and 40 minutes for an alien to lay all her eggs. If the alien ovulated 15 eggs, 5 triplet eggs would take a shorter amount of time to push out than 15 singleton eggs due to 10 fewer breaks.
But this begs the question. Could an alien know she is gravid just via her hearing? And could she know when her eggs are nearing hatching time also via listening for ultrasound?
They typically ovulate anywhere from 5-15 eggs. These eggs if not fertilized are just reabsorbed. If they are fertilized, they implant. But the placenta is within the amniotic sac so you have lots of villi going in between cells of the amniotic sack. Once implanted, calcification starts. The amniotic sack along with the baby alien within it grows. Once the calcification has reached the villi, those villi start breaking off and the placenta starts to become a source of protein for the growing baby. This whole process of calcification lasts 2 weeks after which the mother alien goes into labor. It is very painful and depending on the number of babies within that egg shell(yes, sometimes multiple amniotic sacks end up in 1 shell), it can take anywhere from 5 hours to push out a singleton egg to twice that to push out a triplet egg. There is about a 20 minute break between eggs. This means that a twin egg would take ((10+5)/2) = 7.5 hours to push out because the average of 3 and 1 is 2.
All this means it can take anywhere from 1 day, 2 hours, and 20 minutes to 3 days, 7 hours, and 40 minutes for an alien to lay all her eggs. If the alien ovulated 15 eggs, 5 triplet eggs would take a shorter amount of time to push out than 15 singleton eggs due to 10 fewer breaks.
But this begs the question. Could an alien know she is gravid just via her hearing? And could she know when her eggs are nearing hatching time also via listening for ultrasound?