I'm considering getting an invisible fence for my dogs for when I'm outside with them. There aren't any other dogs in our neighborhood (FREAKS! Just kidding!

) except one other yorkie so I'm not worried about other dogs getting in...and our town is really small and I'm not worried about people taking my pups (I'm still VERY cautious though!). I really just want it so when I'm gardening or something, they don't leave the yard and so I can play fetch with them without worrying if they will escape. Lexie freezes up if she is on a leash, and Beau likes to greet walkers on the sidewalk

. Would you suggest it for something like this? Not just leaving them outside with it?