They always moved in small groups, never more than six.
They always work in groups and the period of time is for a month or more.
I was going to say can we take them in small groups?
And they never worked outside in groups of more than two or three.
They try to stay together in groups of up to 150.
They should be kept in groups of at least five.
They are also known to form schools during the day, sometimes in groups of over 100.
They do not like being alone and should be kept in groups of 3 or more.
But they usually work in small groups, or even alone.
They can be kept in groups of three to seven.