Researchers have found that keeping cats indoors can significantly extend their lifespan. Outdoor cats face numerous dangers, such as road traffic accidents, fights with other animals, and falls from heights, which can reduce their life expectancy by two to three years compared to cats that stay indoors. In Australia, where an estimated 5.3 million domestic cats live, these outdoor activities are responsible for the death of 546 million animals each year. Many cat owners have lost pets while they were roaming outside, with about two-thirds of owners experiencing this loss. Studies using cameras attached to collars have highlighted the various risks free-roaming cats face. In the United States, 25% of 55 tracked cats were exposed to potentially harmful substances, such as pesticides or antifreeze, while nearly half of them crossed roads. In New Zealand, 59% of 37 tracked cats drank water away from home, and 40% ate outside. In Australia, cats wearing radio collars were found to cross roads an average of 4.8 times per day, increasing their risk of being hit by vehicles. Road traffic accidents are a major cause of death for young cats. In the UK, 18–24% of cats are struck by vehicles during their lifetime, with around 70% of these incidents being fatal. Younger, male cats, and those not desexed are more likely to be involved in such accidents. Beyond road risks, free-roaming cats are more likely to contract diseases like Feline Immunodeficiency Virus (FIV) and suffer injuries from fights with other cats. These injuries often require costly veterinary care. Experts recommend keeping cats indoors as the most effective way to protect them from these dangers. This can be done using tools like fence-top rollers to prevent escape, creating outdoor enclosures known as "catios," or training cats to walk on a harness for supervised outdoor time. Indoor cats should have stimulating environments with toys, climbing structures, and litter boxes. In homes with multiple cats, it's advised to provide one litter box per cat, plus an extra, placed in quiet areas away from food. In Australia, the number of households keeping cats indoors has grown from 36% in 2019 to 48% by 2025. This increase reflects a growing awareness of the risks associated with letting cats roam outside, as more pet owners seek to ensure their cats live longer, healthier lives.