Now leaden slumber with life's strength doth fight;
And every one to rest themselves betake,
Save thieves, and cares, and troubled minds, that wake.
(The Rape of Lucrece, 175-177)
In this poem, night is definitely a time where bad things happen - the darkness of the world without the light of the sun reflects or enables DARK DEEDS. Night is likened to a theater where actors perform wickedness:
'O comfort-killing Night, image of hell!
Dim register and notary of shame!
Black stage for tragedies and murders fell!
There is a suggestion in the opening quotation that night is the time for sleep, and those who aren't following this pattern are going against nature for a variety of regrettable reasons. The bad position that Tarquin is putting himself in by sneaking around at night, plotting, etc. rather than sleeping, is accentuated by the company he finds himself keeping - EVIL NIGHT ANIMALS!
No comfortable star did lend his light,
No noise but owls' and wolves' death-boding cries...
Night-wandering weasels shriek to see him there...
Alas, though Tarquin is up to no good in his staying up late, there's something that rings very true in the descriptions in this poem of the nightmarishness of it all - the isolation of staying up in the dark, the exaggeration of all sounds, and just the unnatural weariness of staying up when you should be in bed. I myself have to work at night, and several people in my family have night jobs as well. Though my working life does not quite involve having a night-wandering weasel shriek at me (not EXACTLY), I completely agree with Shakespeare on this one - there's something rather horrible about living in the night as if it were the day. Don't stay up at night! Go to sleep - only thieves and troubled minds wake.