Woolly Mammoth Mice – Friendly, Cold-Hardy Gene Edited Mice For Sale

Meet our Woolly Mammoth Mice — a selectively bred line of exceptionally friendly, large fancy mice developed from our signature Horse × Woolly lineage pairing.

This project combines two carefully maintained lines:

• Horse Line: A pearl cinnamon foundation selected for temperament and social behavior, associated with enhanced communication traits (FOXp2-linked line selection)
• Woolly Mammoth Line: A dense-coated line carrying the tgm5-associated woolly trait, responsible for their signature plush, insulating fur

The result is a highly handleable, calm, and interactive mouse with a standout appearance and strong environmental resilience.

These mice aren’t just visually unique — they are bred with human interaction in mind, making them ideal for keepers who want a true pet-quality mouse, not just a display animal.

Reaching up to ~60 grams, they are larger than standard fancy mice and offer a more substantial, easy-to-handle size. We can offer from weaned to adult, upon request.

Their increased cold tolerance (from the woolly lineage) also makes them more adaptable through seasonal changes, reducing stress in cooler environments.

✨ Key Features

• Selectively bred from Horse × Woolly lineage pairing
• Exceptionally friendly, social, and handleable
• Dense “woolly” coat (tgm5-associated trait)
• Large size, up to ~60g
• Cold-hardy and environmentally resilient
• Unique pearl cinnamon lineage influence

🏡 Best For

• Pet owners seeking friendly, interactive mice
• Hobby breeders focused on temperament + genetics
• Educational programs (behavior & genetics)
• Unique small pet collectors - Only here at Back To The Branch

🛒 Purchase Options

• Sold as single mice or pairs only (purchase a single then inquire for pair and pickup instructions if interested in a pair.)
• No bulk sales — preserves handling quality and lineage integrity

🧬 Lineage Notes

This line represents an ongoing selective breeding project focused on:

• Temperament and communication traits (Horse line influence - father shown)
• Coat density and environmental resilience (Woolly/tgm5 influence - female shown with litter, shes a very advanced girl, her lineage is secret. )

While genetic markers are part of our selection process, all animals are ultimately bred for health, behavior, and long-term stability.