original: Some are arboreal, with long balancing tails and other adaptations for climbing, while others are semiaquatic, with webbed feet and small external ears.
simplifications: Some live in trees and have long tails and other adaptations for climbing. While others partly live in the water, with webbed feet and small ears. Some live in trees with long tails and features for climbing. While others are semiaquatic with webbed feet and small ears. Some have long balancing tails and other adaptations for climbing. Others have webbed feet and small external ears. Some are arboreal. They have long balancing tails and other adaptations for climbing. Others are semiaquatic. These have webbed feet and small external ears. Some are arboreal, with long balancing tails and other adaptations for climbing. Others are semiaquatic, with webbed feet and small external ears. Some live in trees and have long tails and other traits for climbing. Some live in the water and have webbed feet and small ears. Some are arboreal with long balancing tails and other climbing adaptations, others are semiaquatic with webbed feet and small external ears. Arboreal Cricetidae have climbing adaptations (like long tails for balance).  Semiaquatic Cricetidae have webbed feet and small ears. Some live in trees. They have long balancing tails and other adaptations for climbing. Others live partly in water and partly on land. Their toes are joined together and have small external ears. Others are arboreal, with long balancing tails and some other climbing adaptations, while others are semi-aquatic, with wedge legs and small outer ears.