Usually seen in high-energy dogs and very social dogs/breeds. Boredom, attention-seeking, loneliness and excess energy are mostly to blame.
Helping your dog to break the habit will require a different approach, depending on what their reason for the behaviour is, and also depending on how long the habit has taken to develop.
Regular, fun exercise – be it daily play in the garden or walks. Aim to provide sufficient exercise, quality time and mental stimulation on an ongoing basis. Take your dog’s age, breed and fitness level into consideration.
Provide daily treat dispensers (DIY: Google) and chew toys eg: stuffed and frozen Kong. Put in some effort with these things and you’ll be helping your pooch.
Consider adopting a compatible, playful doggy friend
If your dog steals something in your presence, don’t shout or grab unless it’s an emergency. Try rather to let a couple of seconds pass without giving her any attention while you quietly get up to fetch her favorite toy/ball and head outside. Or trade her for the item with a yummy treat, mindfully praising her when she lets you take the item in trade for her favorite treat. It’s important to ignore her at first so she doesn’t learn to be naughty to get not only your attention, but even some play time. Rather create the responsibility of having scheduled play-time in the garden each day. The idea is to have the action of “stealing” something eventually become less satisfying or rewarding.
Call her outside to play or leave her with a delicious stuffed and frozen chew in her bed. Or both. Ask her to sit for the item or before starting play so that she forgets what she did before and finds a new focus. You can also get her leash, call her outside to put it on – asking her to sit first – and then take her for a walk.
Hide “stealable” items, and at the same time “booby-trap” a couple of specific objects to purposely leave lying around. Use Listerine mouth wash or Vicks – both are taste aversive). Citronella oil can also be used but because its smell-aversive take care only to use it outside and away from food bowls, sleeping area etc.