The only mammals that can truly fly are bats.

Quick Scoop: Short Answer

  • Bats (order Chiroptera) are the only mammals capable of powered, sustained flight using flapping wings.
  • Other “flying” mammals like flying squirrels, sugar gliders, and colugos do not really fly; they glide using skin membranes called a patagium.

True Flight vs Gliding

  • True flight means an animal can actively flap its wings to gain height, change direction freely, and stay in the air without relying on falling or strong air currents. Bats do this with highly modified forelimbs that form flexible wings.
  • Gliding mammals leap from a height and stretch a membrane between their limbs to coast downward, steering but not flapping to generate lift. Examples include flying squirrels, sugar gliders, and colugos.

Key Mammal Types Involved

1. Bats – The Only Flying Mammals

  • Bats are the only mammals with true powered flight, and there are over 1,200–1,400 species, making up roughly one‑fifth of all known mammal species.
  • Their elongated fingers support a thin wing membrane, and they can actively climb, descend, and maneuver in the air without depending on updrafts, unlike gliders.

2. Gliding Mammals (Often Mistaken for Flyers)

These mammals cannot truly fly, but they glide impressively:

  • Flying squirrels (rodents with a patagium between front and hind limbs).
  • Sugar gliders (small Australian marsupials that glide between trees).
  • Colugos or “flying lemurs” (not true lemurs; have one of the largest gliding membranes and can glide around 70 meters or more).

Simple Perspective

If someone asks “which mammals can fly?”:

  • Technically correct, scientific answer: Only bats can fly.
  • If they include impressive gliders, you can add flying squirrels, sugar gliders, and colugos, but clarify they glide rather than truly fly.

Information gathered from public forums or data available on the internet and portrayed here.