Tail chasing (or carrying) can look funny to us, but it is a mental disease related to OCDs in people, involving anxiety, obsession, and even paranoia. The animals who do this are generally pretty stressed out. In dogs, cats, and monkeys it is treated with fluoxetine or other similar medicines. I don't know how you'd treat it in a mouse, if you would be able to at all.
Their cage looks pretty empty. Do they have toys or a house? Sometimes these behaviors indicate mice who are suffering from stimulus deprivation and simply by adding a wheel, toilet paper tubes, empty macaroni boxes, or other such things the symptoms will lessen. It doesn't take much to occupy a mouse's mind, but some mice seem much more susceptible to these diseases than others and need more stimulation than others.