Animal Insting

Fennec Foxes are one of the best exotic pets out there. For someone who has never owned an exotic pet before, the little fennec is a great place to start. Quality, bottle fed baby Fennecs tend to be happy, social and extremely energetic animals. They easily bond with you and your family.
A fennec's size is both a good and a bad thing. Their small size allows them to be kept in small spaces inside such as apartments. Outside a full grown fennec fox can slip through chain link fencing. Fennecs also love to dig...with their abundance of energy and curiosity they can be quite a challenge to keep in an enclosure as they will do their best to find whatever you may have missed when building it. If your fennec is an inside pet, always be aware of where it is when opening a door. Once loose your beloved pet may be impossible to catch and may or may not come when called. Your fennec will find a hole to go through and/or climb right up the fence.
The single worst trait I've found in our little gremlins is they can be difficult to litter train. My clients tell me they've had the best luck when there have been cats around to teach them where the litterbox is and how to use it. If you cannot tolerate poop in inappropriate places, a fennec fox is not for you.
When considering a fennec fox, also keep in mind what other pets you have. While fennecs love kittens and get along with dogs as well, they may look upon your pet bird, hamster, lizard, or sugar glider as a tasty meal. Fennecs, like dogs, have a good set of needle sharp teeth, therefore I do not recommend a fennec fox, or any exotic animal really, in homes where there are young children (under 6 years).

source: http://www.juliesjungle.com/fennecfox.php