By Priya Nair (RVN) and Lachlan Ortega · Last updated 17 May 2026
Pet rats are true omnivores — closer to a small dog than a guinea pig nutritionally. They need protein, they handle some fat, and they thrive on variety. The two big mistakes new rat keepers make are feeding a seed mix as the staple (rats self-select sunflowers and become obese, ignoring the vitamins) and relying on “small animal” pet-shop treats (mostly sugar, often dyed).
The 80/20 rule
- 80% base food — lab block (Mazuri, Oxbow Regal Rat, Envigo Teklad) or a high-quality, multi-grain rat mix (Shunamite, Reggie Rat, JR Farm Adult Complete)
- 20% fresh toppings — vegetables, small amounts of fruit, lean protein, occasional treats
Daily portion: about 15-20g of base food per rat (one heaped tablespoon). Plus a small spoon of fresh topping each evening. Rats self-regulate well on lab block but overeat on mixes — weigh them weekly.
Lab block vs rat mix — which to use
| Lab block | Rat mix | |
|---|---|---|
| Nutritionally balanced | Yes, formulated | Variable — depends on brand |
| Self-selection risk | None | Yes (sunflower seeds first) |
| Enrichment | Low | Higher (rats love sorting) |
| Convenience | High | Higher |
| Cost | Medium | Medium-high |
| Best for | Health-first, busy owners | Engagement-first, willing to monitor |
We use lab block as the base and treat mixes as occasional enrichment scatter-feeds.
Master food safety list
| Food | Safe? | Notes |
|---|---|---|
| Apple (flesh) | ✅ | No seeds — they contain cyanide compounds |
| Banana | ✅ | High in sugar; small piece only |
| Bell pepper | ✅ | Great Vit C source |
| Berries (blue, rasp, straw, black) | ✅ | Small handful, 2-3x/week. See our blueberries and frozen strawberries deep dives. |
| Bread (brown, unsalted) | ✅ | Small piece occasionally — handy for medicating |
| Broccoli | ✅ | Florets or stalk; great daily veg |
| Brussels sprouts | ✅ | Cooked or raw, small amounts |
| Cabbage | ✅ | Small amount — can cause gas if overdone |
| Cheese (occasional) | ⚠️ | Small piece weekly max — fatty |
| Chicken (cooked, plain) | ✅ | Excellent protein |
| Chocolate (small dark) | ⚠️ | Rats tolerate dark chocolate better than dogs, but limit. Milk chocolate avoid. |
| Citrus (orange, lemon, lime) | ❌ | D-limonene in skin is toxic to male rats; flesh of orange OK in tiny amounts for females |
| Coconut (fresh or dried, unsweetened) | ✅ | Small amount |
| Corn (cooked) | ✅ | Limit raw |
| Cucumber | ✅ | Hydrating |
| Egg (cooked, hard-boiled or scrambled) | ✅ | Excellent protein 2-3x/week |
| Fish (cooked, white fish) | ✅ | Plain only |
| Garlic / onion / leek family | ❌ | Damages red blood cells |
| Grapes | ✅ | Halved, no more than a few |
| Honey | ✅ | Tiny drop for medicating |
| Lettuce (romaine, butter) | ✅ | Avoid iceberg |
| Mango | ✅ | Treat amounts |
| Mealworms | ✅ | Dried or live — great protein and enrichment |
| Mushrooms (cooked button) | ⚠️ | Plain only, never wild |
| Nuts (unsalted) | ⚠️ | Almond, walnut, hazelnut OK as occasional treat. Avoid peanut for males if possible (mould risk). |
| Olives | ⚠️ | Plain, unsalted only. Most are too salty. |
| Pasta (plain cooked) | ✅ | Treat |
| Peanut butter | ⚠️ | Tiny amount — choking risk if too thick |
| Peas (frozen, defrosted) | ✅ | Great enrichment — float them in shallow water for “pea fishing” |
| Popcorn (plain, air-popped) | ✅ | Unsalted, unbuttered. See our popcorn deep dive. |
| Pumpkin (cooked) | ✅ | Plain |
| Raw beans / lentils | ❌ | Lectins toxic |
| Raw sweet potato | ❌ | Cooked is fine, raw contains compounds that convert to cyanide |
| Rice (cooked) | ✅ | Plain. Raw rice is OK but cooked is more digestible |
| Spinach | ⚠️ | Oxalates — small amount |
| Sweet potato (cooked) | ✅ | Excellent |
| Tofu (plain) | ✅ | Good protein |
| Tomato (red flesh) | ✅ | No stems or leaves |
| Wine / alcohol | ❌ | No — even small amounts harmful |
| Yogurt (plain, low-sugar) | ✅ | Small amount — good for medicating |
| Bamboo (cane) | ✅ | Plain, untreated — great chewing |
Foods that genuinely harm rats
- Citrus peel — d-limonene causes kidney damage in male rats; female rats are less affected but it’s not worth the risk
- Onion and garlic family — thiosulphate damages red blood cells
- Carbonated drinks — rats can’t burp, the gas has nowhere to go
- Mouldy anything — particularly mouldy peanuts (aflatoxin)
- Raw sweet potato — compounds convert to cyanide
- Raw beans — lectins toxic before cooking
- Blue cheese — the mould is a different species that’s toxic to rats
- Liquorice — neurotoxic in larger amounts
- Avocado skin and pit — persin and choking hazard. Small flesh OK.
- Anything sugared / salted / heavily processed — rats develop obesity easily and obesity shortens already-short lives
A real week of feeding for our four rats
| Day | Topping |
|---|---|
| Mon | Frozen peas + small piece scrambled egg |
| Tue | Diced bell pepper + few blueberries |
| Wed | Cooked chicken + cucumber slice |
| Thu | Broccoli florets + half a strawberry |
| Fri | Cooked sweet potato + a few mealworms |
| Sat | Apple slice (no seeds) + small piece tofu |
| Sun | “Forage mix” — handful of dry rat mix scattered in dig box |
Treats and enrichment food
- Pea fishing — frozen peas in shallow water; rats dive for them, get exercise and a snack
- Treat ball — hide bits of dry mix inside; rats puzzle it open
- Mealworms in toilet-roll tube stuffed with paper
- Plain yogurt in a small dish — they lap it like cats
- Cardboard with peanut butter smeared inside — destroyable enrichment
Sources
- Rat Forum UK / Isamu Rats — large community-maintained food list
- National Fancy Rat Society — Diet pages
- RSPCA UK — Rat welfare
- Our complete rat care guide for housing, vet, social setup
We get asked — pet rat food FAQ
What should make up most of a rat’s diet?
About 80% lab block (Mazuri, Oxbow Regal Rat, Envigo Teklad) or a high-quality multi-grain rat mix, and 20% fresh toppings — vegetables, small fruit pieces, lean protein. About 15-20g of base food per rat per day (one heaped tablespoon).
Are rats really omnivores?
Yes — closer to a small dog than a guinea pig. They need protein (cooked chicken, egg, mealworms a few times a week), tolerate dairy in small amounts, and handle cooked grains and most cooked vegetables. The big exceptions are the citrus-peel issue for male rats and the carbonated-drinks issue (rats can’t burp).
Which signs send me to a vet?
- Red or brown crust around eyes/nose (porphyrin — stress or illness)
- Wheezing, sneezing more than once a day (mycoplasma flare-up)
- Lumps anywhere, especially in older females (mammary tumours)
- Hind-leg dragging or weakness in older males (HLD)
- Head tilt (middle-ear infection)
- Not eating for 8+ hours
Related reading
- The complete pet rat care guide
- Master food safety table
- Cross-species toxic foods reference
- RSPCA UK — Rat welfare standards
Portion sizes & serving rules
Rats are tiny, so portion sense matters. The standard fresh-topping serving for a single adult rat is roughly one teaspoon. With a trio that’s a tablespoon total. Anything larger and they cache the rest, often leaving it to spoil in a hammock corner. Removing uneaten fresh food after a few hours saves cleaning time later.
Our 80/20 split: ~80% lab block / quality rat mix, ~20% fresh toppings. The toppings should rotate through proteins, veg, and the occasional fruit treat. Two protein meals a week (cooked egg or chicken or mealworms) keep muscle tone up, especially in older rats.
Male vs female food sensitivities
One genuine sex-specific issue: d-limonene, the compound in citrus peel, is metabolised into a kidney-toxic metabolite in male rats. Female rats handle it without harm. Tiny amounts of orange flesh are fine for both — but no peel, ever, for males, and to keep it simple we avoid citrus across all our rats.
Older males (over 18 months) also benefit from higher-protein, lower-fat toppings as they trend toward muscle loss. Older females need closer monitoring for mammary lumps, which respond well to early surgery.
Enrichment-feeding ideas
- Pea fishing — frozen peas in a shallow dish of water
- Mealworm scatter in a dig box of shredded paper
- Treat ball with dry mix to puzzle out
- Smear of peanut butter on a cardboard tube interior
- Yogurt dot on a flat plate — they lap it like cats
Warning signs after a new food
- Soft or runny stool within 24 hours
- Excessive thirst (especially after sugary fruit)
- Reduced appetite for normal food
- Lethargy or hiding behaviour change
- Porphyrin (red/brown crusty) around eyes or nose — stress flag
Most issues resolve in 24 hours when the suspect food is removed. Anything persisting longer than a day, or symptoms that worsen, is a vet call. Full warning list in our complete rat care guide.
Page last updated 17 May 2026. We re-check our pet-care content regularly and update when something changes.
