Yes! Which animal needs a front door? One that carries a house, of course...

Although in real life it's called a "calcareous epiphragm".

All repeat now:

"a Calcareous Epiphragm"                 

Here's a link that explains a bit more:

en.wikipedia.org/wiki/Epiphragm

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ