Male Russian Hamsters have a scent gland located in their belly button area. This is usually slightly raised with a small dip in the middle and can sometimes appear sticky and should not be cause for alarm. The area may also sometimes have dried secretion on the coat.
Excessive stickiness (wetness beyond the raised area), excessive redness or swelling may be a sign of infection. Excessive swelling with no secretion may be an indication that the gland is blocked. Any signs of infection should be checked by a vet as antibiotic treatment may be required.