12/03/2025
Squirrels, especially gray and fox squirrels, often adopt orphaned babies when their parents die or abandon them. If a lactating female hears the high-pitched distress calls of unrelated pups, she will retrieve them, carry them to her own nest, and raise them alongside her biological young.
This rare cross-fostering behavior in mammals is driven by strong maternal hormones and the survival benefit of increasing litter size. Studies at wildlife rehab centers and in the wild (e.g., University of California research) show that adoptive squirrel mothers nurse, groom, and protect the orphans just like their own, with high success rates.
Adoption is more common in areas with plenty of food and fewer predators. It helps orphaned babies survive and shows that compassion exists beyond humans in nature.
This behavior highlights the flexibility of animal parenting and supports wildlife rehabilitation efforts.