My cat always kicks the sand over his pee in his litter box.
My cat doesn't kick sand over his pee after he goes to the bathroom.
この場合、次のような言い方ができますよ。
ーMy cat always kicks the sand over his pee in his litter box.
「うちの猫はいつもおしっこのあとトイレに砂をかける」
to kick the sand over his pee in his litter box のように言えます。
ーMy cat doesn't kick sand over his pee after he goes to the bathroom.
「うちの猫はトイレの後おしっこに砂をかけない」
doesn't kick sand over his pee で「おしっこに砂をかけない」
ご参考まで！
カナダ 
