When our gerbils had babies, I thought I counted five newborns. A few days later when their nest was open, I only saw four so I brushed off the fifth as a miscount.
When I posted their picture a few days back, I could only see three. Then after cleaning their cage, I discovered there were only two.
Either the babies are junior escape artists or gerbils, like hamsters, eat their young.
I would have expected this from a hamster but I thought better of gerbils.