How much does a rat eat per year? - briefly
A typical laboratory rat consumes roughly 50–70 g of food daily. Over a full year this amounts to about 18–25 kg of intake.
How much does a rat eat per year? - in detail
Rats consume a relatively small mass of food each day, but the cumulative amount over twelve months is substantial. A typical adult laboratory rat weighs 250–300 g and eats about 5 % of its body weight daily. Assuming a 275 g average, daily intake is roughly 14 g of dry feed. Multiplying by 365 days yields an annual consumption of approximately 5.1 kg of solid food.
Wild rats encounter a more varied diet—seeds, fruits, insects, and refuse. Their daily intake ranges from 10 g to 20 g, depending on food availability and seasonal conditions. Consequently, yearly intake can vary between 3.6 kg and 7.3 kg.
Water intake scales with food consumption and ambient temperature. Laboratory rats drink about 30 ml per day, amounting to roughly 11 L per year. Wild rats may ingest 20–40 ml daily, leading to an annual range of 7–15 L.
Key factors influencing total consumption:
- Body size: Larger individuals require more calories; a 350 g rat may ingest up to 18 g of feed per day.
- Diet composition: High‑protein pellets increase mass needed for energy compared with carbohydrate‑rich grains.
- Activity level: More active rats expend more energy, raising food and water requirements.
- Environmental temperature: Cold conditions elevate metabolic rate, prompting higher intake.
Summarized ranges for an average adult rat:
- Dry feed: 4–6 kg per year (laboratory) or 3.5–7 kg (wild)
- Water: 7–15 L per year depending on habitat and climate
These figures provide a detailed picture of the yearly nutritional demand of a typical rat.