You would typically use grams to measure a hamster's weight.

Here's why:

* Small size: Hamsters are small animals, so using kilograms (which are used for heavier objects) would be impractical.

* Common usage: Grams are the standard unit of measure for small animals like hamsters, making it easy to compare their weights to other hamsters.

You could also use ounces if you prefer, as that is a common unit in the US.