Gerbils like the Sapphire gerbil tend to be nocturnal and diurnal creatures meaning if they tend to stay awake and active at night then they will sleep during the day or vice versa. It’s perfectly natural for your gerbil to spend long periods of time sleeping followed by long periods of time spinning his gerbil wheel and running all over his cage. However, if his routine changes and you notice your gerbil is sleeping all day and appears to be sleeping at night too then there is cause for concern. Your gerbil should be moving around at some point. If he’s not then he could be lethargic which could be a sign of illness. Call and schedule an exam with your veterinarian Los Gatos, CA right away. Take note and let your vet know if your gerbil is eating and drinking regularly as well as urinating and pooping as usual.