Someone will awaken Tuesday to find the gift of rat under the Christmas tree.

Of the countless store specials emailed to me this holiday season, one stood out from the rest.

“Save 50 percent on all rats — today only!” said PetSmart in one of its deals of the day.

What a deal. I wonder if our fondness for pets isn’t going too far. I can think of better ways to love your enemies.

Half-price rats is good marketing. The discount from the regular price of $10.99 can be more than made up in sales of cages, houses, bedding and food.

I didn’t run right out to the Mays Landing PetSmart to stock up on cheap rats, but I did visit while holiday shopping.

There I found the discount rat, labeled a “fancy rat,” perhaps to suggest this was no ordinary rat but one especially well suited to be a pet.

But the rat looked like an ordinary dark gray rat, and a careful examination of its description revealed its species as Rattus norvegicus, the Norway or brown rat, the most ordinary rat in the world.

This is the Old World rat (from Central Asia rather than Norway) that came to this continent in the grain boxes of the Hessian soldiers the British hired to fight American revolutionaries. The Hessians may have failed spectacularly in the Battle of Trenton, but the brown rat has spread everywhere there isn’t a severe winter.

This is the rat whose overpopulation sometimes leads to mass migrations, even across rivers that drown many of them, allowing Pied Pipers to falsely claim power over rats.

This is also the rat people usually have in mind when speaking of vermin, of destruction of grain stores and crops, or just raids on garbage cans.

This is the rat that prompts local officials to enact laws such as Northfield’s that mandate “all buildings, lots and premises shall be kept free from rats” and if they’re found, “the person in control of the premises, lot or building shall apply continuous eradication measures to remove the rats” … “through the use of traps, poisons, fumigation or any other acceptable method” carried out by a licensed exterminator.

This, too, is the rat whose name has been an epithet for 400 years, and applied especially to disloyal people and workers who don’t honor a strike.

Even the Humane Society of the United States, while urging more benign methods of rat control, warns that “rats are considered as carriers or transmitters of more human diseases than any other life form, except maybe the mosquito.”

At PetSmart online, the fancy rat is rated five stars out of five by 101 reviewers, with 97 giving it the top rating and no one rating the rat less than three stars.

Reviewers say the rats are smart, friendly and even loving, and don’t bite. One warns: “So many people have a poor and misguided opinion of them, and may judge you for it. Please don’t pay attention to how they are shown in the movies as evil creatures.”

Many animals are vilified for no good reason, but not the rat.

The federal Centers for Disease Control and Prevention says rats transmit several serious diseases directly, including hemorrhagic fever, Lassa fever, leptospirosis, plague, rat-bite fever, salmonellosis and tularemia.

Two CDC case studies of rat-bite fever in 2003 show the potential for problems with pet rats.

In one, a Florida 52-year-old woman who worked in a pet store was bitten on her finger by a rat and treated it immediately with antiseptic ointment. Two days later she was very sick and went to an emergency department, where despite antibiotics and two blood transfusions, she died 12 hours later.

A 19-year-old Washington state woman lived in an apartment with nine pet rats, two of which were treated for respiratory symptoms. Despite no known rat bites, she developed fever, headache and weakness, and died in three days.

Pet rat groups recommend buying rats only from established breeders, which no doubt can reduce the small chance of disease transmittal.

Just remember, there’s a reason that the rats under the Christmas tree in the popular ballet “The Nutcracker” are not pets, but evil foes.

Contact Kevin Post: 609-272-7250