Desert Diaries

Packrats! What are they good for? Absolutely everything.

Packrats are absolutely vital to a healthy desert ecosystem.

Packrats eat plant parts and seeds, and thus are seed and cactus dispersers (they help plants get started in new places). They not only help aerate soil, but their poop even helps fertilize the seeds!

Additionally, packrats are food for bobcats, coyotes, owls, hawks and snakes. Those animals rely on these fuzzy furballs for a full belly. Packrats are an essential part of the food web.

Room for rent! Packrat homes house other animals. Mice, arthropods (eg. insects and spiders), and even tortoises do not mind cohabitation with these rodents as their houses are climate controlled and well protected. In areas with a packrat presence, the biodiversity of animals is higher. Thus, they are considered not just ecological engineers, but a keystone species as well.


Photo: Jay Pierstorff


Packrats live in a…house, midden, or nest?

These amazing architects construct homes made out of sticks, branches, and rocks. They even protect it with cholla pieces and dog poop! The house has many rooms in it, including the nest (bedroom) and midden (toilet).

Some packrat houses are so well constructed and protected that they have survived and been continuously occupied for thousands of years. Wow, what workmanship!

Packrats are the original Sonoran Desert Scientists

Packrat pee is incredibly viscous and thick. When they pee on things, it ensconces them in an amber-like fluid which then crystallizes. The objects are so protected in this package that packrats unknowingly create time capsules of our past! The seeds, plant parts, animal bones, and pollen fragments that they save give us a view of bygone eras. The Sonoran Desert doesn’t have ocean sediment or ice cores to record its past, but it does have middens. So, thanks to these resourceful rodents, paloecologists know that the ecology of the American southwest has changed significantly over the last 50,000 years.

Did you know? Saguaros have only been in the Tucson region for about 8,000 years! We appreciate packrats for helping us celebrate and understand our surroundings.

Packrats are copious collectors

Packrats are also known as trade-rats due to their propensity to pick up small objects and collect them. When a packrat is carrying a prized possession and encounters another, it decides whether or not to trade in the first toy. Wildlife biologists still don’t know why packrats collect, just that they do. Soda cans, golf balls, plastic toys, car keys and more all get picked up.

Do you curate (take care of) a collection at home? What do you collect and why? Tell us in the comments! Watch the video below to see what these kids collect!        

Your packrat package is undeliverable

While it’s unusual for a non-profit to refuse a donation, we kindly do not need gifts of trapped packrats. It’s impossible to know if the rodent has ingested poison, which can be transferred to our animals. Please bring your kids to see Packrat Playhouse- but leave the live animals at home!  

Help! Packrats are in my car. What do I do?

While packrats play an important part of the ecosystem, we recognize that it can be mentally taxing and financially frustrating to have a packrat problem. Because they like enclosed protected spaces, packrats make homes of car engines, BBQ grills and AC units.

The Desert Museum recommends following a Personal Packrat Protocol to avoid expensive problems.


A packrat’s house in a car engine. Photo: Mr. Packrat

Stay tuned for more details about our upcoming new exhibit, Packrat Playhouse: Hidden in the Midden! 

Written by: Catherine Bartlett, ASDM Education Specialist