Rodent

Rodents are a group of small pets. They were first introduced in The Sims: Livin' Large and reappeared in The Sims 2: Pets, The Sims 3: Pets and The Sims 4: My First Pet Stuff.

The Sims: Livin' Large
In Livin' Large, the guinea pig was introduced. If the cage wasn't cleaned for a long time, and it bit a Sim, the Sim would become sick. The fastest and easiest way of curing this sickness is to buy the guinea pig painting and look at it.

The Sims 2: Pets
The Sims 2: Pets adds womrats. They can be purchased by buying the appropriate cage in buy mode, and then using the cage's "Restock" option, which can only be done if the cage is empty and clean. Womrats cost §75. The womrat cage is called the FMCU 3000.

The Sims 2: Apartment Pets
In The Sims 2: Apartment Pets, hamsters and guinea pigs are some of the pets Sims need to take care of.

The Sims 3: Pets
Rodents are one of the various kinds of minor pets introduced in The Sims 3: Pets. They can be caught outdoors like other collectibles. Rodents can be kept temporarily in the inventory, but they might eventually run away if kept for too long. Rodents need to be placed in terrarium and be fed regularly.

Being a collectible pet, there is no limit to the amount of rodents a Sim can collect.

List of rodents
Although they are referred to as rodents in-game, shrews and hedgehogs are not actually rodents.

The Sims 3: Pets introduces 7 Rodent types. Each has its own rarity and worth.

There are only 3 common rodent available via the "Stock a Terrarium" option. THe rest must be caught in the wild.

The Sims 4: My First Pet Stuff
The Sims 4: My First Pet Stuff adds four new rodents in special cages.

Unlike cats and dogs, rodents does not have life stages. They, however, can die of old age or starvation. When a rodent passed away, a notification will inform Sims. The rodent soul can be seen leaving the cage.

To prevent rodents from aging up, Sims can buy the Feat Anti-Aging Treat (§300) to halt the aging process in rodents. The treat can be purchased on the computer or vet clinic.

Cage
There is maximum one rodent per cage. As long everything is available in their cages, rodents would be able to stay healthy. When a rodent cage is purchased, the new rodent will be well fed. Sims need to refill the food bowls and clean the cage regularly.

The following interactions are available on rodent enclosures:
 * Clean Habitat
 * Fill Food
 * Feed Treat
 * Observe
 * Play With
 * Purchase Rodent
 * Release
 * Rename
 * Study Rodent (Child/Teens Only)
 * Talk
 * Investigate and React (Cats and Dogs) (Require The Sims 4: Cats and Dogs)

The cage has a corkboard that allows Sims to pin postcards on.

Rodent travels
Rodents in The Sims 4: My First Pet Stuff can travel to far away lands. They sometimes leave their cage and travel. A note can be seen in the cage, notify they have left the cage.

Notifications will inform the adventures along the way.

Rodent Fever
If Sims neglect the rodents for a period of time, rodents contract Rabid Rodent Fever. Sims who play with these animals can be bit, more likely if they have poor relationship with the rodent. Sims will receive a 2-hour "Bite-Sized Bite" moodlet. After 2 hours, the moodlet either go away or turn into a 24-hour "Fuzzy Feeling" mooodlet. This is the beginning stages of a deadly illness.

Sims can cure themselves either by buying the Rodent Remedies using a computer or Ask about Rabid Rodent Fever at the local vet clinic. If they do not cure themselves, they will receive the 24-hour "Fuzzy Fever" moodlet. The Sim can now also spread the disease to others.

After 24-hours left untreated, Sims receive a 24-hour "Rabid Rodent Fever" moodlet. This is the last chance to save Sims from death.

Death by Rabid Rodent Fever is a new type of death with a new ghost. Rabid Rodent Fever ghosts dress as hamsters. These ghosts can cure their disease by purchasing the serum and turn themselves into a regular ghost.

Trivia
Not all rodents are pets. In The Sims: Unleashed, gophers are pest that eats the plants. Pests return in The Sims 4: City Living, which would give Sims a tense moodlet.