Time for a "time-out" box/cage! When you correct him and he goes right back ... he gets to be put in a small cage and ignored for 5 to 10 minutes, then let out ... if he does it again ... repeat the "time out" ... if he does it the 3rd time ... time out is in his own cage for an hour or so.
Humping, as they said, can be a dominance issue ... be glad he is not a jealous female. We have one female (Pee-tunia) that is in love with my hubby ... if he hugs or kisses me in front of her ... she sprays me every chance she gets for the next 3 days.
Their bones are smaller than toothpicks and break easily ... especially the floating ribs that can pierce a lung and kill, if broken. Be very gentle with him ... never yell at, hit chase or grab him ... that's often how injuries and distrust happen. Treat him with love and respect ... the same way you would like to be treated.
The kitchen is not the best of places for a chinchilla ... heat and moisture from cooking ... stoves and refrigerators to hide under and behind and electrical cords to chew that will make him a crispy critter! (Not to mention hot ovens and/or dark cold refrigerators to hide in.)
Bedrooms, dens and living rooms provide some very dangerous places to hide ... between/under cussions or in-between springs in the furniture ... which if set on, could squish him.
Computer rooms will offer lots of electrical wires and delicate electrical equipment that can be harmed by the dust clouds from a dust bath or the very fine fur they shed.
The bathroom or an enclosed hall way is usually best. 100% supervision at
all times when out of the cage is a must.
For his safety (and pleasure), he must be the absolute "center of attention" when outside of his cage. This is a one-on-one time ... no distractions! Chinchillas love attention and will do anything (good or bad) to get that attention. Try talking to him and playing with him on the floor and see if that does not help to curtail the bad habits, or at least the frequency of them.
Jo Ann
BEWARE: He will return to the bad habbits as soon as you look away.
Play time is one-on-one time.