Hi there,

Inappropriate nursing is typically a sign that the kitten was taken from her mother or weaned too early. They retain a very strong drive to nurse, particularly during stressful times (like being introduced to a new home).

It is generally not a problem and will typically fade with time as they become more accustomed to solid foods. On occasion (i.e. stressful situations), they may revert to it briefly.

So long as it is not bothering your tom and the kitten is not ingesting too much hair (coughing, gagging, passing a lot of fur in stools), the behavior should fade and hopefully disappear with time (usually by 6 months at the latest).

If it doesn't, or if it becomes a problem for the kitten or the tom, you can try re-direction, i.e. providing a favorite toy, play activity, or treat when you catch him nursing. In extreme situations, they require medication from your veterinarian, but this is very rare.

Hope that helps. Please let me know if you have any other questions.

Thanks,
Dr. Paul