Retic Not Eating: Sexual Maturity?

[Theweinz]

My retic will be three years old this next spring. He has never turned down food before, yet he has backed away from the last two rats I offered him. Backed away in kind of a huff. He seems quite restless, and, although he still tolerates my handling quite well, he is on the move more. Also, the last few weeks there have been a couple examples of small spots of whitish looking liquid in his enclosure (looks like sperm). He did leave a sperm plug last time he shed as well. So do you think the lack of appetite is related to reaching sexual maturity? Have any of you experienced the same thing? All husbandry is as it has been for the last couple of years. Have a Borneo male giveing me the same kind of treatment, yet he is just over three years of age. Thanks