How do we know how the populations of animals and especially things like insects?

Question

Edit: 🤦🏻‍♂️ What a fail of a title. What I meant was…

How do we know what the population of animals are?

In: 7

Answer 1

Estimates. You don’t count every grasshopper in a field, instead you count how many grasshoppers in a 1 foot square and then multiply that number by number of square feet in field. You can further multiply number of fields for entire planet if desired.

Edit* some populations, like tigers, are so small near every individual can be counted.