I've put together a ventilation system for a custom litter box that constantly flushes its internal atmosphere with outside air using a fan system:
/| +--------------+
/|-------[clean air]------>| |
window /| | [litter box] |
/|<------[dirty air]-------| |
/| +--------------+
Now I'm trying to figure out if the box should be opaque or transparent.
Vendors like Amazon.com seem to have examples of both (e.g., transparent hood; opaque hood), though I imagine that human preferences weigh in on buyer selection, whereas I'm primarily concerned with my kittens' comfort.
I've found a few articles (example) that claim that cats prefer transparent boxes so they don't feel like something could be sneaking up on them.
Other factors that might go into this are:
The litter box can have gentle LED lighting so it's never really dark.
The litter box can have multiple doors.
Question: All else equal for a covered litter box, would cats tend to prefer for the litter box to be transparent or opaque?