They are incredibly smart, but they are a real handful. Mine is actually allergic to human "dander". He has injections once a week. Strangely enough, my husband is allergic to canine "dander"...yes, he has shots too! Ironic, huh?
I have a JRT too.
She is one of the calmer ones unless there is a lizard, snake or frog around. Then she goes into her own little zone.
Best dog we have ever owned.