If you feed them, they will come.
Long, long ago, my dad (a botanist and wetland scientist) turned a disused sandlot in our country house backyard into a wetland - diverted a spring to fill it with water, excavated the middle and made a dike around the edges, planted it with wetland plants. It lacked frogs, so we went out one foggy spring night when the frogs were all crossing the road in search of compatible mates, caught a bunch of them, and liberated them in our little backyard wetland. The frogs made themselves at home and laid lots of tadpole eggs. Soon enough we had creatures hanging around out back specifically for the free frog buffet.
