The grass mouse, or Nile arvicanthis, is a small rodent that lives in African savannas and grassy plains. The animal is active during the day, runs quickly on the ground, and builds burrows.
The grass mouse differs from many other rodents in that it is active during the day, not at night. It is important for nature as the main consumer of grass in the savanna and as food for snakes, birds, and small predators.
meadows, prairies, forb glades on land
homogamy, reproduction always with fertilization, no alternation of generations
Whiskers count
Worker
Tail size
birth time
breeding
Hot and almost no precipitation
Dogs, dolphins, lynx hang out for 9-25 years and party on their birthday three times a year
m
Map
will celebrate their {n} birthday
g
t
When your next jubilee falls in {name} life years
Human
hot Africa south of the desert, many savannas and forests
days
How old you would be if you lived as {name}
summer from pleasant to very hot
Theoretical maximum lifespan estimated from the Dynamic Energy Budget (DEB) mathematical model. This value reflects a biological potential derived from metabolic parameters, not from direct observation — real recorded lifespans are often significantly shorter.
adult
Maturity
plants
insects
About health
milk
When your next birthday would fall if you lived as {name}
Repro interval
results
land coast flooded by tides — salt marshes, littoral zone
Eyes count
Colors
Sex
very hot and almost no rain
Upcoming jubilees
Gremllins
mo
hot, rains in summer, little precipitation in winter
Uses an excavated underground tunnel or chamber for refuge or nesting.
rains are very rare, almost a desert
conifer cones
little precipitation in winter, more in summer
alpine meadows and arctic tundra on land
Trophic type
Filters
summer very hot, dry, lots of grass
Warm or hot summer
Tail count
young shoots and sprouts
grass
Upcoming birthdays
eggs, roe or offspring develop in a nest built on the ground or close to it
Truly long lives: 40-100 years. Bowhead whales, albatrosses, giant tortoises recall their birthday at most once a year
Lifespan
in a burrow
nest on the ground
young shoots
young are born live on land, not hatched from eggs or roe
Very hot and almost dry
Age (juvenile)
Age (from birth to death)
cones of coniferous trees with seeds
Hot, little precipitation in winter
Age (embryo)
Wanderers
Jubilee = every 10th birthday
Ears size
Earliest developmental stage inside an egg or womb.
Business sausages
Lifespan average
nest located directly on the ground surface on land, only the mother provides parental care for the offspring
in a terrestrial nest
Incisors color
Whiskers size
live birth
What do they look like?
Maturity
emergence (insects)
end of lifespan
How do they live?
fertilization / egg laying
How do they behave?
birth / hatching
metamorphosis / end of larval stage
end of acceleration
Share
seeds
Find a pet...
Mature, fully developed individual capable of reproduction.
nest hidden in an underground burrow
hot, uneven rains, lots of grass and trees
Pets
Hot steppe
{name} jubilee
cm
Old-timers
Find an animal or breed...
desert and semi-desert
turns
Rascals
terrestrial grassland and steppe
terrestrial herbaceous
terrestrial intertidal
Tail color
drink mother's milk in childhood
hot Africa south of the desert, many savannas and forests
Ears count
Litter size
Tropical savanna
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
How to care for them?
Living from 25 to 40 years. Orangutans, bald eagles, African elephants celebrate their birthday twice a year
grazing
°C
Not specified
alpine and arctic tundra
Where are they found?
nest hidden in an underground burrow, only the mother provides parental care for the offspring
steppe
38 to 65 grams, 15 – 40 centimeters
herbivore
Whiskers color
Feeds by cropping or nibbling low-growing vegetation or algae.
Incisors size
Low precipitation in winter
Legendary longevity: over 100 years. Galapagos tortoises, Greenland sharks, ocean quahogs celebrate with family once every 4 years
Offspring
Elders
leaves and stems of grasses and other herbaceous vegetation
Bro
normal sexual
Taxons
if born as {name}
age
birth date
arid terrestrial biotopes with sparse vegetation
rest
Fur color
Close
was
Career from 7 to 15 months. Dwarf hamsters, voles, field crickets celebrate their birthday twice a month
The basics
herbivory, feed only on plant food
My weight?
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
primary food sources
teeth
burrow
arid steppe
after transformation until death
Potential Habitat
lots of grass, few trees, rains are rare
d
In husbandry
On the go from 1.3 to 3.5 years. Forest mice, anoles, rainbow fish party on their birthday once a month
Mass
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
Plants
Gestation
land
{name} birthday
grass
Always hot
No results found
On the map
young shoots, sprouts, green plant shoots
Female ♀
all life stages
gnaws plants
world of Afrotropics
nest located directly on the ground surface on land
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
Potential habitat modelled from GBIF occurrence data. Map © Zveriki.com, licensed under CC BY 4.0.
birth year
lots of grass, few trees, rains occur
Shelter used specifically for reproduction or nesting.
Maturity
Skin color
caring mother
terrestrial habitat, land surface outside water
sq mm
yr
protection from sun
How similar?
Male ♂
until the celebration
baby / chick
age as {name}
How do they breed?
On the go from 3.5 to 6 years. Hedgehogs, crows, lizards treat themselves to birthday snacks 6 times a year
What if eaten?
Very dry
Neither
from birth to adulthood
Young offspring still dependent on parental care.
caring mother
What do they eat?
Where do they live?
Immature individual that has not yet reached reproductive maturity.
Ears color
Hard dental structures used to bite, tear, or scrape food.
world of Afrotropics
Very hot and dry
Duration
live insects
This is me
Steppe
Gamers
How are they built?
Temperate steppe
mm
Theoretical lifespan
ml
Stars
Link copied
My age?
wk
My size?
very hot during the day, cold at night, almost no rain
terrestrial
Asexual
swap
Rabbits, falcons, red-eared turtles hang out for 6-9 years and party on their birthday four times a year
Where do they take shelter?
Denotes a grassland or steppe habitat preference.
inhabit and develop on land, outside water bodies
celebrated their {n} birthday
open grassy spaces — steppes, savannas, prairies
When you would have been born if you lived as {name}
very hot all year round, frequent rains, but sometimes dry
Daddies
Lifespan maximum
very hot and almost no precipitation
body
Hermaphrodite ⚥
embryo
Orange
Incisors count
Length
kg
Observations
◉{N} more on tap