276. Washington Post Male and Female Nouns

Male and Female Nouns
From the Washington Post Style Invitational in which it was postulated that English has male and female nouns, and readers were asked to assign a gender to nouns of their choice, and explain their reason.
The best submissions:

Detective Novel -- f., because you're not supposed to peek at its end the minute you pick it up.

Swiss Army Knife -- m., because even though it appears useful for a wide variety of work, it spends most of its time just opening bottles.

Kidneys -- f., because they always go to the bathroom in pairs.

Penlight -- m., because it can be turned on very easily, but isn't very bright.

Hammer -- m., because it hasn't evolved much over the last 5,000 years but it's handy to have around and is good for killing spiders.

Tire -- m., because it goes bald and often is over-inflated.

Hot air balloon -- m., because to get it to go anywhere you have to light a fire under it. And, of course, there's the hot air part.

Web page -- f., because it is always getting hit on.
Web page -- m., because you have to wait for it to reload.

Shoe -- m., because it is usually unpolished, with its tongue hanging out.

Copier -- f., because once turned off, it takes a while to warm up. Because it is an
effective reproductive device when the right buttons are pushed. Because it can wreak havoc when the wrong buttons are pushed.

Magic 8 Ball -- m., because it gives monosyllabic answers that usually indicate it did not pay attention to your question.

Ziploc bags -- m., because they hold everything in, but you can always see right through them.

Sponges -- f., because they are soft and squeezable and retain water.

Critic -- f. What, this needs to be explained?

Subway -- m., because it uses the same old lines to pick up people.

Hourglass -- f., because over time, the weight shifts to the bottom.

Cars -- f., most of the time they're ok, but if you mistreat them or don't service them often enough, they soon break down and/or turn into a wreck.