Rat Feeding Calculator — Daily Lab Blocks & Fresh Food

80 % of the diet should be lab blocks — uniform nutritionally complete pellets designed for rats. Top brands: Oxbow Essentials Adult Rat, Mazuri Rat & Mouse Diet, Harlan Teklad 2014/2018, Kalmbach Hubbard Life Rat & Mouse. Lab blocks ensure rats can't selectively pick high-fat components (the #1 problem with seed mixes). Feed ~15–20 g per rat per day (about 2–3 blocks), free-fed.

No — strongly avoid. Rats are selective feeders that cherry-pick high-fat pieces (sunflower seeds, corn) and leave the pellet/balanced parts. This causes obesity, nutritional deficiencies, and chronic health problems. Seed mixes marketed as “rat food” (Kaytee Fiesta, Hagen Rat Mix) should be avoided despite their low cost — the vet bills from resulting health problems exceed the savings many times over.

Safe (1–2 tbsp per rat daily): leafy greens (romaine, spinach, parsley, kale), cooked sweet potato, broccoli, carrots, bell pepper, cucumber, apple (no seeds), blueberry, banana, pea. Occasional: cooked chicken (protein), scrambled egg, plain Greek yogurt. AVOID: chocolate (toxic), citrus (male rats only — causes kidney damage), avocado pit/skin, rhubarb, raw beans, onions, garlic, grapes/raisins (kidney toxic in some rats).

Rats are true omnivores and can eat a combination of commercial lab blocks + varied fresh foods as the optimal diet. Exclusively raw/fresh diets require careful nutritional balancing that most owners get wrong — rats develop calcium, B-vitamin, or protein deficiencies. The recommended approach: 80 % lab blocks (nutritionally complete baseline) + 15 % fresh vegetables/fruits + 5 % varied treats.

Yes, slightly. Intact male rats are prone to kidney disease — avoid citrus (d-limonene in orange oil is nephrotoxic in males specifically). Avoid excess protein for males (over 18 % protein accelerates renal decline). Females have higher caloric needs during pregnancy/lactation but otherwise similar. Both sexes benefit from low-fat diets (under 5 % fat) to reduce tumor risk.

Growing rats (under 6 months): ad-libitum lab blocks + more fresh food. Their metabolism is higher and they need calories for growth. Adult rats (6+ months): measured portions of ~15–20 g lab blocks + moderate fresh food — rats are prone to obesity and overfeeding shortens lifespan. Senior rats (18+ months): soft food options, smaller portions, more variety to maintain interest in eating.