Mongoose (Herpestes javanicus)


Regulatory Status: Hawai’i Injurious Wildlife (HAR 124). It is against Hawai’i State law for any person to introduce, keep or breed any mongoose within the State except by permit from HDOA; permits are not issued for Kaua’i County or the island of Lana’i. Fines for violations are between $250 and $1,000 for each mongoose introduced, kept or bred. HDOA Animal Industry Division Quarantine Rules HAR 142-92.

Prevention and Control Category: KISC Target Species.


Report this species if seen on Kaua’i or Lana’i!

Report Invasive Species 643-PEST



Mongoose are a weasel-like animal totaling about 26″ in length with a long, brownish body, short legs and a tail as long as its body. They have small rounded ears and a pointed nose. The mongoose is active during the day and generally sleeps in dens at night.


Mongoose are opportunistic feeders that will eat birds, small mammals, reptiles, insects, fruits, and plants. They prey on the eggs and hatchlings of native ground nesting birds and endangered sea turtles. The small Indian mongoose has been blamed with the extinction of ground-nesting birds in Jamaica and Fiji and commonly kill birds, including 8 federally listed endangered Hawaiian birds, such as the Hawaiian crow (‘alalā), petrels (ʻuʻau) and Hawaiian goose (nēnē). It was estimated in 1999 that mongoose cause $50 million in damages to Hawai`i and Puerto Rico annually.


The mongooses found in Hawai’i are native to India and were originally introduced to Hawai’i Island in 1883 by the sugar industry to control rats in sugarcane fields on Maui, Moloka’i and O’ahu. The introduction of mongoose was misguided- while rodents make up a large portion of the mongooses’ diet, their substantial negative impact on other desirable birds, insects, and animals outweighs their minor impact on rat populations. Mongoose are now widespread on Hawai’i island, O’ahu, Maui, and Moloka’i (It is not necessary to report sightings on these islands). There are no known populations on Lanaʻi and Kauaʻi. Mongooses can live in both wet and dry conditions including gardens, grasslands, and forests.

Are Mongoose an Example of Biological Control Gone Wrong?

No. While the introduction of mongoose to Hawai’i is often casually referred to as an example of biological control gone wrong, the introduction of this species by private individuals in the sugarcane industry was not part of any scientific biological control process. Biological control, or “biocontrol,” is a robust scientific field in which research is done to identify a predator or pest of a given invasive species from its home range, followed by extensive research to determine whether the predator or pest- if introduced to Hawai’i- would impact only the invasive species in question. Mongoose did not undergo this evaluation prior to entry and should not be considered an example of biocontrol. You can learn more about modern biocontrol efforts at the HDOA Plant Pest Control, Biological Control Section website.

What you can do

If you see this species on Kauaʻi or Lanaʻi call 643-PEST or visit

Look-alike Species

Cats, rats, and occasionally fleeing pheasants have been mistaken for mongooses. Cats have a rounder head, pointed ears, longer legs, a flat nose, and usually have a jumping pounce. Large rats run low to the ground, like mongooses, but are usually spotted at night (unlike mongooses). Pheasants also run with a low profile and since sighting them lasts only seconds, they can easily be mistaken.

For more information, see: