I really hope that I am wrong and that you just surprised them by turning on a light and they were asleep. If you haven't done a partial water change and you have a 10-gallon aquarium, do you have a couple of gallons of water at about the same or slightly higher temperature which you could use to complete that water change?

    What are your ammonia, nitrite or nitrate test readings? If you don't have test kits, would you have access to a shop which would make water tests  for a nominal sum? Those are very important things to monitor. If any of those are too high, please consider a partial water change and also rinse and  add some activated carbon to your filter. (That stuff is chemically active for only about a week or two.)

    If you have no such treated water and need to change it, could you or someone in your family drop $2 on two or three gallons of drinking water (NOT RO, distilled or baby formula water) at the local grocery? Leave it where it will warm up to the temperature of the aquarium.

    In the meantime take a gravel vacuum and go over part of the gravel. When the tank has dropped about 30%, very gently begin adding that new water. If you have a clean, soap-less small jar, put that on the tank bottom. you might be able to slowly pour the water into that and avoid most disturbance of the gravel. Or... you could take a 3 foot length of airline tubing and slowly siphon that water into the tank.

    Then put a little of whatever water conditioner was recommended for your tap water in each jug. Fill them with cold to no more than Luke warm water and let then sit a day or two. If possible, leave the tops open (so they can absorb oxygen and lose carbon dioxide and free nitrogen) and place the jugs in a warm place. Do another partial water change out of the jugs in a day or two or three. Refill them in the same manner. :)

    How long has your aquarium been set up? What is in it? Was the nitrogen cycle established at 4 to 8 weeks? (For more in that see Immediate Help, the second section.)