In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
The odd thing is that the cat doesn't leave a present as the mix of folded
membrane and mulch seem to put it off. But every night it has another try.
Stupid as well as deaf and no sense of smell...

Doesn't sound like a cat. The cat deposits first, then scrapes to cover
the smell. So it would disturb the membrane until it had left a deposit.
Sounds more like something foraging for food in there.
--
Kay
"Do not insult the crocodile until you have crossed the river"