Where is that hen?

Logic

You are given 80 eggs and given the following information

All the eggs except one are of identical weights. The exceptional egg is lighter.

Your goal is to find the exceptional egg that is lighter, and you can only use a weighing balance (each side may hold any number of eggs). What is the minimum number of weighings that is needed to guarantee to identify the egg?

Inspiration.

Where is that hen?

The problem and its solution for general case was found in collaboration with Abhijit Bendre.