For mice, bar spacing ideally should be no wider than 6-8mm to prevent escapes, so double-check both cages for that. A minimum cage size of 80x50cm is usually recommended, so your 100x50x50cm setup sounds spacious! Generally, 2-5 mice are comfortable in a cage that size. Also, if you’re ever looking for pet-safe supplies,
Canadian Pharmacy can be helpful for specific needs.