Fat sand rat facts for kids
Quick facts for kids Fat sand rat |
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| A fat sand rat in Morocco | |
| Conservation status | |
| Scientific classification | |
| Genus: |
Psammomys
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| Species: |
obesus
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The fat sand rat (Psammomys obesus) is a small mammal from the gerbil family. You can mostly find it in North Africa and the Middle East, from Mauritania all the way to the Arabian Peninsula. These rats usually live in sandy deserts. But they can also be found in rocky areas or salty marshlands.
Fat sand rats are very picky eaters. They only eat stems and leaves from plants in the Amaranthaceae family, also known as the amaranth family. When kept by humans, fat sand rats can get very fat and quickly develop diabetes if they eat food meant for other rodents. In the wild, they live for about 14 months. When cared for by humans, they can live for 3 to 4 years.
Contents
Life in the Desert
Daily Activities
Fat sand rats are active during the day. However, how much they move around depends on how hot it is outside. In summer, they are active for a shorter time. They start in the early morning and finish an hour or so later. As the weather gets colder, they stay active for longer parts of the day. They also start their daily activities later.
When they first come out of their burrows, fat sand rats often spend time sunbathing. After that, they start looking for food and exploring. Bigger fat sand rats tend to look for food longer than smaller ones. When they find food, they cut pieces from plants. They then take these pieces back to their burrows. They might eat the plant right away, or save it for later. This saving of food is called hoarding.
Fat sand rats get most of their water from the plants they eat. Plants like Atriplex halimus have a lot of water inside them. By eating these plants, the rats get all the water they need. This means they do not have to drink standing water.
Besides finding food, fat sand rats also spend time exploring outside their burrows. They explore in a special way. When they find a new area, they tend to move in straight lines along the edges. Most other rodents explore by moving in loops or staying close to their home. Male fat sand rats also spend more time exploring than females.
Social Life
Fat sand rats are not very social animals. They live in their own separate burrows. Male rats usually have larger areas where they roam compared to females. Rats of the same sex usually try to avoid each other. However, when female rats do meet, they often act aggressively and might even attack each other.
Male rats can also be aggressive towards each other. They might push or stand sideways. But most of the time, their interactions are peaceful. When males approach females, they often act in a fighting way. They might push, box, or attack each other. But if a female starts the interaction and approaches a male, they are more likely to have peaceful interactions. They might sniff, investigate, follow, or even groom each other.
Choosing a Home
Fat sand rats dig their burrows right under the plants they eat. They choose where to dig based on how many amaranth family shrubs are in the area. This is more important than how much cover the plants provide. So, where fat sand rats live can change throughout the year. This depends on when plants grow in the wadi beds or terraces. Wadi beds are often full of amaranth shrubs and have thick plant cover. Terraces, however, have very few plants and are more open.
The amount of rain also affects where fat sand rats live. So does how many rats lived there the year before. In winter, fat sand rats prefer wadi habitats because many plants grow there. But after a wet autumn, more rats might dig burrows in terrace areas, even if there are not many rats around. After a dry autumn, rats only burrow in terraces if there are many of them.
The digging of burrows by fat sand rats can change their habitat. For example, it can affect the tiny bacteria in the soil around their burrows. Their digging also disturbs the plants growing on the ground. Active burrows have much less plant cover than old, unused burrows or untouched land nearby.
Avoiding Danger
Many desert animals hunt fat sand rats. These include different kinds of birds, snakes, desert cats, and animals from the Mustelidae family (like weasels). The risk of being hunted changes depending on where they live. To stay safe, fat sand rats watch out for danger when they are above ground. They will stop what they are doing and stand upright to look around. Or they might stare intently in one direction.
If they get scared, they will thump their foot loudly and squeak. Then they quickly run back into their burrow. It seems that other nearby rats do not react to this foot thumping. So, it might not be a way to warn others about predators.
Fat sand rats living in open terrace areas spend more time watching for danger than those in wadi beds. But this watching does not stop them from finding food. Both groups spend the same amount of time foraging. However, there is a difference in how they get food. Rats in terraces tend to hoard their food more often. They also take less time to eat. Since fat sand rats are not very social, they spend less time looking for food and eating. They also watch for danger more often compared to other desert rodents that live in groups.
Reproduction
Fat sand rats breed from autumn to early spring. They usually have litters of one to eight babies, called pups. The average number of pups in a litter gets bigger as the breeding season goes on. When mothers start feeding milk to their pups, their body energy goes up. But towards the end of this period, they start using up their stored energy. This makes them lose body weight.
Pups grow best when the litter is small. They also grow better when the mother eats plants with more water in them. The young pups leave their mother when they are about 5 weeks old.
Male and female rats have different ways of raising their young. Females use smaller areas around their burrow. These areas have enough food for their babies. Males, however, roam over larger areas. These areas often overlap with the areas of several females.
Why Scientists Study Them
Fat sand rats usually stay thin when they eat their natural diet of plants. But they can easily become very fat and get type 2 diabetes mellitus if they eat a regular rodent diet of grains. Because of this, scientists use them to study diabetes and obesity.
Scientists have studied the genes of the fat sand rat. They found changes in a gene called Pdx1. This gene helps control insulin, which is important for sugar in the body. These changes might help the sand rat live on a diet with fewer calories. Or they might make them more likely to get diabetes. However, we do not know for sure if these changes cause diabetes. Many parts of the sand rat's genes have these kinds of changes.
Since fat sand rats are active during the day, they are also used to study human seasonal affective disorder. This is a type of sadness that some people feel during certain seasons.
The fat sand rat lives in North Africa and the Middle East. This is important for human health. Scientists have found tiny parasites in these rodents. These parasites can cause a sickness called leishmaniasis in humans.
These animals are also studied for their amazing kidneys. Their kidneys can make very strong, concentrated urine. This helps them eat salty plants and survive in the hot desert without much water.
