Cotton balls are one of the most widely used pieces of accessory by ant-keepers, they are efficient, easy to use, and can be used in a variety of different situations. They can be used to plug up an entrance hole to avoid escapees, plug up the end of a test tube set up to avoid the ants from escaping as well as offering fresh air so they don't suffocate to death. They are also often used as the stop to water reservoirs because it transfers water very well, a cheap and inexpensive option to sponges.
These cotton balls are packed into approx. 20 each bag, they are packed for your convenience and make ISC truly a one-stop shopping destination for all things insects.