Can anyone help me with a rabbit? ?

my brother has recently got a rabbit however he is moving into an apartment where he found out is not allowed keep pets he has asked me to take care of it for a while until he can make arrangements but with the move it could be a while, ive noticed the rabbit eats drinks poops pee's and just lys down ALL DAY LONG NON STOP with little or no interest in me, is this normal? i mean as far as i know they are supposed to be somewhat curious and friendly?and to make it worse he does not seem to sleep at all, he hops chews and drinks(which are all very loud at night time) which has led me to start wearing ear-plugs at night which are uncomfortable expensive and not very good and has also led to me being late for work because i could not hear the alarm! as for the cage it is at the stage where i would nearly have to clean it out totally 3 times a day, this is causing me a lot of extra hle as i have a full-time job and not a lot of time to be spending constantly cleaning hoovering and changing his very LARGE cage, However, i am willing to stick it out for as long as i can, maybe if i understood the rabbit a little better or if anyone had some suggestions about animal shelters in the Dublin area it would greatly help me and my brother. any help would be greatly appreciated.