On 2016-01-06, N_Cook wrote:
Would a bit of napthalene mothball keep spiders and other small creepy
crawlers out of the warmth of an always-on, so warm, bit of kit, or any
better ideas to keep bugs out of there.

Napthalene smells like **** and is a poor insecticide. It's used
in closed spaces where the concentration of the vapors builds up.

I'd spray some permethrin-based insecticide in the vicinity,
and maybe even inside the unit.

The stuff is available in the form of bug spray which contains only
around 0.25% of the stuff. It leaves no visible trace and the sprayed
areas stay effective for weeks to months.