A wink is to close one eye briefly. You could wink at somebody in a cheeky kind of way.
But what about 40 winks?
Forty winks is another term for a catnap or short sleep.
Often, older people like to have forty winks in the afternoon or evening.
Of course, there are no greater experts on sleeping than cats; they sleep just whenever they feel like it and wherever they want - just like this!