until it dies of exhaustion. This concern is not seen in recessive white face (husky). Breeding The sex of a Roborovski is determined visually; female openings are very close together and may even look like a single opening, while male openings are further apart. Males usually have a visible scent gland near the navel above the two openings, appearing as a yellow stain in older animals. The breeding season for the Roborovski hamster is between April and September. The gestation period is between 20 and 22 days, producing three to four litters. The litter size is between three and nine, with an average of six. Captive bred Roborovski do often breed all year round. The offspring weigh – at birth. Upon being born, the offspring have no fur, the incisors and claws are visible, but the eyes, pinnae of the ear and digits are all sealed. After a period of three days, the whiskers become visible and after five days, the first dorsal hairs develop. The digits separate after six days and after eleven days, the body is completely formed. The young hamsters open their eyes by day 14. As pets Roborovski hamsters have become increasingly popular as pets in recent years, however, they are best suited to life as merely observational creatures, with limited interaction between them and humans, due to their increased activity levels that lead to a high stress predisposition and decreased ease of handling when compared to other domestic hamster species, but they can be tamed with time. On average, Roborovski hamsters will live 26 months in captivity. Although claimed to be hypoallergenic, Roborovski hamsters have been associated with the development of asthma in previously asymptomatic owners. In rare emergency situations, a shallow dish of warm water may be necessary to clean harmful substances from a hamster's fur; however, under normal circumstances, hamsters should never be bathed in water as, aside from being incredibly stressful, this can remove vital protective oils from their coat, which can be very dangerous and potentially fatal. Hamsters frequently groom themselves, and instead of water, a sand bath should be offered to help them stay clean and healthy. Housing Unlike other species of hamster (see 'Syrian hamster behavior'), Roborovski hamsters can sometimes be kept in same-sex pairs or small groups if raised together from a young age. A lone, or pair of Roborovski hamsters should be kept in a cage of