Maybe a Rat

One night I was done showering.
Opening the closet I put on a clean T-shirt,
Something was quite bothering.
Out of the T-shirt fell a black dropping.
Smelly, that was someone's pooping!

So then I embarked rat-hunting,
Until I learned - from an educated biologist - 

that was not a rat's doing,
but a Tokay Gecko, in my house, hanging.