A pair of calipers or a ruler would be suitable tools to measure the size of a bull ant. Make sure to handle the ant carefully during measurement to avoid any harm.
i would use mm that is te best metric measurment you would use
For an ant farm, I would suggest a kilogram. For an individual ant, a milligram.
you would use a kilogram
length
length
3 milligrams is the weight of an average ant.
The mass of an ant would typically be measured in milligrams (mg) or micrograms (μg).
You would use CM or INCHES to measure a knife
meter
you would use grams
cm