Interesting...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7437539/
“Age-dependent ACE2 gene expression has also been documented in the nasal epithelium, with the lowest gene expression evident in younger children and increasing expression evident with age.97 As this is the first point of contact for SARS-CoV-2 in the human body, lower ACE2 expression in the nasal epithelium of children may explain the infrequent infectivity in this age group.”
Interesting; fits perfectly. Even if I got it wrong about the bats, I may be on the right track about ACE-2.