Wombaroo Bat Milk Replacer 165g. Wombaroo Bat Milk Replacer is a nutritionally balanced milk substitute for orphaned microbat (insectivorous bat) pups. Key Features: Specifically formulated to match the composition of microbat milk. Elevated fat content to provide the high energy requirement of bat pups. High in protein to cater for the rapid growth rate of microbat pups.