Russell is a big dog in a small body. If you compare his origin with the origin of today's Fox Terriers, Jack turns out to be closer to their age-old ancestors created for hunting and working in the hole, which had an iron will and need persistent training.
It gave the qualities of today's Jacks, their mind, attitude, physique, fantastic character, incomparable athleticism and agility. All this makes him a great house pet and companion.
He is always alert and ready for the next adventure or discovery. He looks at you with inquisitive clever eyes as he asks, "What is my master wants?" He loves his master and by all his behavior he is trying to show it. Loves to kiss, sit on their hands, loves caress and tenderness. He is capable to make rapid decision, self-confident, never timid, shy or hesitant. Here's a mix of the most diverse and sometimes incompatible qualities.
"Flying Dog" is one of the epithets that the nation awarded to Jacks. Why is "flying"?
Look at him, he's never all four paws on the ground, he always jumps, literally soars above the ground, as aerialist, in some fascinating dance. He is rarely nervous or aggressive, almost always friendly and active. He is small, dressed in white coat with a small red or black spots.
The theme of sterilization/castration is quite trite: you have to do it if no obvious indications? Of course, each owner makes his own decision and adheres to some of his beliefs. We will not try anybody to convince of anything (why do we need another topic of controversy?), the following information for those who have a dog, who is still undecided in your opinion or does not know what the choice is. (for experienced dog walkers information can also be very interesting.