Yes, they are small, 5 in a teaspoon.
If you want to measure their volumes, you can use liters (= cubic decimeters), milliliters (= cubic centimeters) or cubic millimeters.
Cubic Centimeters
cubic centimeters, cubic inches, cubic feet, cubic meters, cubic yards, or bushels also perch and shipping tons
None. You cannot convert linear units to cubic units.
numbers
Milliliters and cubic centimeters are units the measure volume. Volume refers to the space that an object or substance occupies.
Commonly used units include cubic meters, cubic decimeters (equal to liters), cubic centimeters (equal to milliliters).
The volume of solid objects is typically measured in cubic units such as cubic centimeters (cm³) or cubic meters (m³).
Cubic inches, cubic centimeters, liters, quarts, and gallons
A cubic centimetre is a unit of volume. A centimetre is a unit of length. The two units are therefore incompatible.
If units are in centimeters cubed, you would use a ruler or a measuring tape to measure the length, width, and height of an object in centimeters. You can then multiply these three dimensions together to calculate the volume in cubic centimeters.
This is not a valid conversion. Cubic units is a measure of volume while square units is a measure of area.