My 5 yr. old male cat will not cover his pee with litter in the litter box. He's been doing this for the past 3 yrs. now. I don't understand why he started to do this. No matter how clean the litter box is or even if it has just been cleaned, he's to lazy to cover it. He just pee's and goes. As you male cat owners know, it's not a very pleasant thing to come home and your house is overwhelmed with male cat pee odor. I have to be the one to cover it with litter or the other cat does this for him. I know it can't be because of another cat using the same box since she has only been with us for 1 year now. Any suggestions on what I can do or just as to why he is doing this? Thanks.