When transitioning your snake from mice to rats, the terminology can be incredibly confusing. What exactly is a "Weanling"? Is a "Pup" bigger than a "Fuzzy"?
To ensure you are feeding the correct 10-15% of your snake's body weight, you need an exact gram-to-gram breakdown (see our what size mouse for Ball Python guide for snake-to-prey weight ratios). Here is the definitive Frozen Rat Size Chart.
The Master Frozen Rat Size Chart (Referenced in our Ball Python feeding guide)
Note: Weights can vary slightly depending on the breeder, but these are the industry standard classifications used by Loxahatchee Rodents and other premium suppliers.
| Rat Classification | Weight Range (Grams) | Age Equivalent | Best For... |
|---|---|---|---|
| Pinky Rat | 5g – 12g | 1 – 4 Days Old | Hatchling colubrids, Hatchling Ball Pythons |
| Fuzzy Rat | 13g – 19g | 5 – 13 Days Old | Young juvenile Ball Pythons, Adult Corn Snakes |
| Rat Pup | 20g – 29g | 14 – 20 Days Old | Sub-adult Kingsnakes, Juvenile Ball Pythons |
| Weaned Rat (Weanling) | 30g – 45g | 3 – 4 Weeks Old | Small adult Pythons, Sub-adult Boas |
| Small Rat | 46g – 79g | 5 – 6 Weeks Old | Adult Male Ball Pythons, Sub-adult Boas |
| Medium Rat | 80g – 149g | Young Adult | Adult Female Ball Pythons, Adult Boas |
| Large Rat | 150g – 249g | Mature Adult | Large Boas, Small Reticulated Pythons |
| Jumbo Rat | 250g – 350g+ | Retired Breeder | Large Constrictors, Monitor Lizards |
Why Switch from Mice to Rats?
If you own a heavy-bodied snake like a Python or Boa, transitioning to rats is non-negotiable.
- Protein to Fat Ratio: Rats naturally possess a higher protein and fat content than adult mice, providing better nutrition for heavy-bodied growth.
- Digestive Ease: Feeding one Medium Rat (100g) is biologically easier on a snake's digestive tract than feeding four Adult Mice (25g each) in a single sitting.
How to Weigh Your Feeders
Never eyeball prey sizes. Buy a digital kitchen scale that measures in grams. Weigh your snake, calculate 10-15% of that weight, and reference the chart above to order the precise classification of frozen rat required (visit our guide on where to buy frozen mice and rats for top-tier sources).