Hi all,
Many Inlands go through a teenage phase (from about 3 to 4 ft) where they are generally grumpy and more quick to become defensive. This usually wanes when they reach about 5 ft. There are exceptions though...I have 6ft female here that has remained grumpy.
Inlands temperament also improves if they are at their prefered temperature, when they are too cold, they tend to be more defensive.
Cheers,
Scott