How can Mexicans fit so many people into one house/minivan?

This may get deleted, but I love Mexicans! I just wonder sometimes like when I go to the store in a Latino neighborhood (they have the best fruits/veggies @low price!!) I will see a Mexican family its like 10 ppl + a baby in a stroller get out of an old minivan. Also, my grandma lives next to a family that has about 8 kids and 4 pairs of adults in it. They make good use of space it seems!