Pepper is two. he used to settle very well in his crate downstairs at night. the last few weeks he keeps barking for company. we go in say shush , turn our back , he stlles again but then a few minutes or maybe hours later he barks again. if i leave him he will bark for hours. he is not cold, hungry, or needing a pee, i've check ed all those. i don't know what else to do. any ideas?