Take it to the vet.
Do not date your hamster, it is entirely too young.
Sure, why not!
You don't breed hamster babies until there at least 1 year old
If the 1 year old hamster is a syrian hamster DO NOT put another hamster with it. They are hamsters that NEED to be alone. If it is a dwarf, hamster, it might be ok. Dwarf hamsters like having each others company. However, if the 1 year old hamster is not use to other hamsters, it might not go over to well.
1 year old or 365 days old or 8765 hours old or 525600 minutes old or 31536000 seconds old
A hamster can be sold at 12 weeks old or above, it's usually good to sell them then they're young and not when they're about 1 year old.
For ten months, the hamsters would be around 5 or 6 years old and 1 whole year is about FIFTY years!! 1 actual year is 25 hamster years which means about 14.6 days is one hamster year :D
Your hamster may have mites, so you should take them to the vet and have the vet check.
No. Female hamsters lose their fertility within one year. If the hamster is male, then it is possible that he is too old as well - I tried mating a younger female with a 1 and a half year old male and it didn't work.
Boy yes, girl no. She'll become sterile at 12-14 months.
That is normal hamster behavior, nothing to worry about.
WOW! Your hamster lived over-age usually hamsters live 1-3 years! So maybe your hamster in hamster years is 100!!!!