The Department of Land and Natural Resources' Division of Fish and Wildlife said the coqui frog hopped onto a Micronesia Air Cargo Services plane and was detected by a dog detector handler at the weekend.
The frog, which was introduced to Guam and Hawaii in early 2000, has since been contained and preserved in a jar and will be used by the Department for sampling and research.
The coqui frog is marked as invasive species due to the very loud "ko-kee" calls males make at night and the severe effects the species can have on a native ecosystem's insect and bug populations.
