Eliminating Tree Rats





Introduction: Eliminating Tree Rats

Rats carry more than 40 harmful human diseases and rat-borne diseases are thought to have taken more human lives in the last 10 centuries than all the casualties of all the wars and revolutions combined. Each year, rats destroy approximately 20% of all the agricultural products in the world, including going after my mangos and avocados. Also, rats eat eggs and prey on baby birds as you see in the top photo.

SO, the problem is how to get rid of tree rats. Setting traps in trees is difficult, time consuming, dangerous from repeatedly climbing ladders, need to be checked daily, and are not very productive. Using poison on the ground in proper bait boxes will have little to no effect on tree rats. Putting poison in trees can kill a lot of birds.

I have a very simple solution that gets the rats but not the birds.

Step 1: Eaten by a Rat

This is an avocado eaten by a rat. You can tell by the long smooth tooth marks. They only eat the very top of the avo while it is on the tree, and then the avo falls to the ground.

Step 2: Eaten by Birds

This is an avo eaten by birds. You can tell by the small holes made by their beaks. HOWEVER, it was probably eaten by a rat first which is why it ended up on the ground, and then the birds got to it.


Rat poison, block type with holes (Several brands available)

Wire, String, or whatever

Old plastic bottles


Pliers to cut wire

WARNING: PLEASE read the caution label on the poison carefully.

Also, NEVER use rodent poison INSIDE your home. The rodent may die in a hidden place and you may not be able to find it resulting in a horrendous rotting stench for months.

Step 4: Make a Tent

Cut the ends off a plastic bottle with scissors, band saw, knife, or whatever method suits you.

Step 5: Keep the Tent Low

If you have a large bottle like the above, cut it in half with scissors, band saw, knife, or whatever method suits you.

Step 6: Make a Hole

Make a hole in the long side of both sides of the tent using nail, knife, drill, screwdriver or whatever.

Step 7: Secure Bait to Tree Limb

Secure the bait to a tree limb using wire or string. No need to twist or make the wire tight because you will be replacing the bait periodically. It is only necessary to hold the bait in place.

Step 8: Cover the Bait

Secure the plastic bottle section over the bait using wire, string or whatever suits you.

Step 9:

Rats can get through a hole the size of a quarter (Euro) so keep the tent low to keep out birds.

Step 10: Long & Low

A long, low tent is better than a short fat one. That makes it really easy for rats to get to and impossible for birds.

Step 11: Use Several Baits

Put several baits in each tree. Check fallen fruit for evidence of being eaten by a rat and add a bait and tent on the limb above that location.

Step 12: The Enemy

Rats carry lots of diseases and are dangerous to the health and well being of you and your family.

Step 13: Success

You may or may not find the dead rat(s). They often go back to their nests to die. Dispose of the dead rat promptly and properly. Best wishes, Mauibuck



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    15 Discussions

    Buck in Maui, I have busy rats in Waialua in a avocado tree eating 1/2 the skin off of the avocados. I am on the edge of farm land. Have seen barn owls fly in at night to eat rats, but obviously not enough barn owls to solve problem. I had thrown rat poison (D-Con) at base of tree last year and there were no chew marks on avocados. This year thought I had solved the problem, but they are back and only 1/8 of tree producing fruit, so loosing any is painful after waiting a year. How could I get more barn owls to go after the rats? The barn owls are amazing to watch fly in. Thanks

    1 reply

    Unfortunately the owls in Hawaii are not very effective since they kill only for food. I live in a residential area and there are virtually no owls in the vicinity. I have a cat that occasionally catches a bird or a mouse and brings it inside for me to play with but he is totally ineffective or not interested in catching rats.

    In the 10 years I have been using the posted method, I have only found 2 dead rats and I have virtually NO rat problem. It is my understanding that the rats go back to their nests and die there.

    On the other hand, virtually every day I find avocados that have been eaten by birds. Avocados are deadly to birds and cattel, but MAYBE not so much for chickens. Avos are also toxic to lactating mammals but not humans.

    "Where does the recommendation come from to not feed your pet bird avocados? According to "A Guide to Plant Poisoning of Animals in North America," avocado poisoning was first reported in 1942 in California, and its toxin — at the time not precisely identified— affects cattle, horses, goats, canaries, budgies, cockatiels, ostriches and other birds and animals. Ostriches have died of congestive heart failure within 96 hours of eating the fruit and leaves of avocados. Symptoms of avocado poisoning in other birds include respiratory distress and sudden death."

    So, we are sort of damned if we do and damned if we don't. Grow avos, kill birds. Put out rat poison, maybe kill an owl or pet. There are no perfect solutions. Don't put out poison, the rats devistate the avos and grow big families. I only use the posted method when I see evidence of rats eating either my mangos or avos. It works. Putting the D-Con on the ground will poison birds. I found that out the hard way.

    Switching subjects slightly, to improve the yield of my avos and mangos, I use a 16 inch long 1" bit in a 1/2 drill and make holes as deep as I can, about 4 feet apart, at the canopy drip line and fill each hole with a tropical fruit fertilizer. The objective is to get the fertilizer down to where the roots are. Spreading fertilizer on top of the ground is highly ineffective. I do this twice a year, for both my mangos and avos and get great crops every year. In fact, when my avo blooms, I cut off 40% of the blossoms to keep it from overbearing. My avos grow to over 2 pounds. You get 30" rain/year in Waialua. I'm in Kihei and get MAYBE 17" but I irrigate the lawn so we are probably are about equal in water to the trees.

    Excellent! love the idea of covering the poison to protect the birds.

    Good idea to dispose of dead rats ASAP so that owls, hawks,eagles, etc. aren't ingesting the poison or bringing poisoned meat to nested young.

    your information about rats is incorrect to say the least, try not using only google as a research tool but sites with credible sources -masters in terrestrial mammal ecology

    1 reply

    Unfortunately, those who study and try to predict pandemics do not share your view . http://www.pnas.org/content/112/22/7039

    To each their own OP. Trap, shoot or poison. Trapping can catch the wrong animal, poison can work it's way up or down the food chain. I say buy a decent pellet gun and learn to shoot it.

    You don't need to spread misinformation about rats to demonstrate how to kill them. Rats, themselves, only spread a couple diseases, and only through ingestion of feces. Who eats rat feces? Be clean, don't blame rats. There are humane traps, too, by the way, for catching and releasing rats.

    2 replies

    Saumipan, thank you for your comment. I live in Hawaii and we have a VERY dangerous problem with rats. "A 23-year-old man living on the island of Hawai‘i developed a life threatening case of eosinophilic meningitis caused by infection with Angiostrongylus cantonensis (rat lungworm disease: RLWD). He was comatose for 3 months, incurring brain and nerve damage sufficiently extensive that he was not expected to recover." We have had 42 cases that we know of from 2007-2015, eight years. Please google and read up on rat lungworm disease. Our concern is real and life threatening.

    I do research in rats. A parasite is not the same as the rat itself being a direct vector. So if you don't mess with slugs, you're good.

    These poisons are blood fluidifier, the animal dies of hemoragy and you can be pretty sure it will suffer a max.

    Regarding diseases, I read somewhere they are catched by their fleas, not them directly. It was the case for the black pest that killed one third of europeans in the middle age, testimonies reported that rats died as well.

    what would happen if my dogs ate a poisoned rat? they love squirrels and rats? any advice

    1 reply

    Some poisons can be secondary fatal, meaning that any animal who eats the dead animal can be effected by the poison. Please check the instructions on the bag of poison or their online information. I have cats and they are not interested in dead animals, only live ones. But I too have the concern.