DOn't count , but do notice if some aren't around.
Normally find 'em sooner or later.
Just re-did the 20 gallon tank this last weekend-over-run with pond snails. Threw out all the plants (all had snail eggs) and put in new gravel. Saw my Clown Plec for the first time in a month-he hides good!
Do a census of sorts on the Shrimpies; have 22 of them, but have only had a high count of 15; they hide **** good!