Our shopping list this week:

• orange marmelade
• cream cheese
• parmesian cheese
• toothpaste
• coffee
• stapler
• frozen peas
• pepperoni
• liquid nitrogen

My brother had his 40th birthday party last week. My gift to him was to supply liquid nitrogen ice cream for all the guests. I've been wanting to try LN2 ice cream for years, but didn't know how or where to get my hands on the stuff. In grad school we just had a tank of the stuff in the lab. It was supposed to be for experiments, but a significant percentage was diverted for various graduate-level entertainments.

About a month ago one of the other geek dads at the twins' school served LN2 ice cream at his son's birthday party. The primary reason for enrolling one's children in a Gifted and Talented program is, of course, getting to socialize with geek dads.

I interrogated him and found out that, as long as one has the right equipment (a liquid nitrogen storage dewar), LN2 is easily obtained from your friendly local welding supply store. The nitrogen itself isn't too expensive, though the dewar is a few hundred dollars. On the other hand, the dewar will last for decades if properly cared for, so a one-time investment can mean years of uniquely nerdy party entertainment at a very reasonable price. My brother's milestone birthday gave me just the excuse I was looking for.

Unfortunately, we emptied the dewar before the kids got tired of ice cream. One of the twins (age 10) decided that more LN2 was an essential household supply.

And that is why we are the only family on the block with "liquid nitrogen" on our grocery list.

Now if you will excuse me, I need to go load the dishwasher and check on the cryo-tanks.

"Dear Santa,

"Please disregard any infractions regarding my behavior this year.

"From, John"

We had thought Scooter, at almost 11 years old, didn't really believe in Santa any more. When Christmas Eve came, however, it looks like he wasn't quite ready to deny Pascal his wager.

Scooter, my oldest son, is the kind of person who just has to know what will happen when he throws a rock at a wasps' nest.

Then, he needs to repeat the experiment to make sure the same thing happens each time.

August is the time of year when the wasps' nests get to be about football size and utterly irresistible as a target for small thrown objects.  Last summer, there was one in the crabapple tree in the front yard, about six feet off the ground.  Scooter got stung a couple of times, and his face swelled up for days after.  Nevertheless, the next day he was at it again, chucking rocks and sticks despite the painful lesson of the day before.

The wasps are generally beneficial since they eat all kinds of damaging bugs and caterpillars, so I prefer a "live and let live" strategy when dealing with them.  When they get too close to where the kids are playing, however, something has to give.  Once discovered, the kids can't be trusted to leave the nest alone, and I don't want to have them scared to play in our own yard.

Last summer, we were fortunate to have a run of cool weather, so I was able to cut down the nest on a 50-degree morning (they have trouble flying when it gets that cool).  Within hours, some other critter had discovered the tasty morsels inside and ripped the nest apart to eat the wasps and their larvae.

This year, the kids discovered a nest in a tree near their new tree-fort.  It's not clear whether Scooter intentionally threw stuff at it, or just happened to hit the nest when chucking things at his brother, but either way the wasps got good and angry.  Scooter go stung about a half-dozen times during his mad dash to the house, while one of his brothers was smart enough to retreat before being stung at all.

The other twin, however, was in the treehouse and got pinned down by angry wasps.  The poor kid was stuck for several minutes while the insects repeatedly stung him.  I tried to get to him to help, but inadvertently walked right under the nest and got chased away when I got stung 8-10 times in just a few seconds.  I also lost my glasses in the yard and have yet to find them.

My son did manage to climb safely down and run to the house, leaving his shoes behind. For several hours, wasps were seen harassing the abandoned shoes, apparently thinking that they represented a continued threat. Needless to say, this nest cannot remain.

This nest is much higher up than the one from last summer, and the weather looks unlikely to get down to 50 for several weeks.  So this evening I plan to empty a can of insecticide into the nest and once again remind all three kids that when you see a wasps' nest, leave it alone.