We all remember the mischievous Milo from The Mask. A cute small dog should have been great for keeping in an apartment, but no. As they say, growth is small, but the ego is huge. Temperamental, mega active and rather arrogant Jack Russell will become a real curse for those who cannot control his energy and direct it to a peaceful direction. In order to keep the dog under minimal control, it must be walked for at least 3 hours a day. And these will not be quiet walks in the park, but a real forced march. In addition, it is worth mentally preparing yourself for the damage that will be caused to everything that the dog can reach. By the way, you can not expect that with age the dog will calm down.