Our Robbie (who lives outdoors) has dug a hole under the neighbour's fence. He had never tried this before but has successfully done so and I can't find him. I went to the neighbour's backyard and it's like a jungle in there. I've asked the neighbour to look out for him but I'm hoping he hasn't escaped further beyond the neighbour's yard (which is fenced off and has no obvious exits but you could say the same about our yard and he found a way). I will shortly call the local vets and animal shelters. Any tips for getting Robbie back? Is it likely he'll find his way through the neighbour's jungle and come back through the hole?