I am also growing strawberries in a homemade earth box. Just seeing how they do this season. They are blooming and have put out a few fruits but the birds or my dogs got them!
My are not quite ready for the 'pests' to have their takings yet. I have fed quite a number of critters off mine in the past, from these tiny slug like creatures, snails, terrapins, rabbits, squirrels and any number of types of birds on up to deer. I have found though there is a deer/rabbit/squirrel repellent I can spray around the perimeter that deters much of the larger traffic. I think the worst offender are the terrapins, nothing but physically carrying them off the property bans them.