Imagine this. It’s fall and you’re a mouse. You’re tired and cold. You need a warm, safe, spot to hunker down for a few months. What’s the first place that comes to mind? A little dry burrow, a hollow log, or how about a confined box full of 60,000 angry, stinging bees?
Believe it or not, many a mouse has chosen to shack up with bees for the winter. It’s a highly rewarding game, but one that can often prove deadly. By mid October, daytime high temperatures have dropped to the 50′s, and nights have turned frosty. Bees have long since stopped making any new honey, and inside the hives they are starting to go into cold season survival mode. As the weather turns, worker bees form an increasingly tighter cluster around the queen. The bees in the center of the cluster produce metabolic heat by shivering, and bees on the outside of the cluster act as insulation. The heat producers and the insulators continually rotate positions. The whole cluster slowly moves up the hive as their 60 or so pounds of stored honey is consumed during the winter months. All that time, the hive maintains a temperature of 60 to 70 degrees even during the most bitter cold outside.
While the bees are balled-up in their cluster, they don’t defend the hive against intruders, undertake any hive cleanup, or do any maintenance. A mouse can easily enter a non-winterized hive and build a nest in the comb, completely ignored and unimpeded by the host bees. It can spend a leisurely winter eating precious wax and honey, and staying comfortably warm. There’s a serious catch though. When outside temperatures warm, the bees will loosen their cluster and wakeup fairly quickly. An activated colony will sting an intruder to death in minutes. So, a mouse has to make sure it doesn’t enter the hive too soon, and it can’t stay a day too long. That’s life on the edge to be sure!
Beekeepers in Vermont generally winterize their hives in October. Part of that process is to install mouse guards and entrance reducers. I was running late. When I finally made it out to the apiary, one of my hives had wax crumbs and other debris on the landing board, a sure sign of a mouse invader. I could have just put on the entrance reducers (like I should have done weeks before) and sealed the mouse inside. However, a spell of warmer weather had arrived, so it was possible to open up the hive without chilling the bees. The cluster wouldn’t be super tight either, so I figured I’d be able could remove some frames without too much disruption, find the mouse, and hopefully drive it out. I smoked the hive with just a few puffs, put on a veil, and went to work.
When I took off the lids I saw a fair amount of activity for this time of year. It was unseasonably warm that day, in the low 60′s. Either the bees hadn’t really balled-up for the winter yet, or they had temporarily broken up alot. Any resident mouse would be in trouble. Either it had already left the hive, or its nest was offering some temporary protection. I took off the upper box. The mouse would be in the bottom box, along the back wall. A 10 frame deep full of honey weighs over 80 lbs. Beekeepers normally use smaller boxes or “supers” for their harvest honey, so lifting off a full deep like this is an exception. I gently placed it on the ground, on the upturned hive cover, which is standard procedure. I kept looking for a mouse running out, but didn’t see anything. Using my hive tool, I pried out the first frame of the lower box. Sure enough, a mouse had eaten away part of the comb and built a big fluffy nest of leaves and grass.
I shook the nest on the ground, and lifted out the next frame. I really didn’t want to disturb the bees which were thick on the middle frames, so I gently slid them back and forth. I was peering down between, still looking for the intruder. It was nowhere to be found. It must have made it out alive during the recent the warmup. Lucky mouse. I’ve heard tell of beekeepers finding less fortunate mice in the spring, when the hives are opened up for the first time. Bees like other small insects are incredibly strong for their size, and are meticulous housekeepers. A dead mouse though is of course too much for them to handle. Out of hygenic instict, their response is to encase the mouse in propolis, which is the sticky resin-like compound bees produce for sealing and gluing. A mummified mouse in a propolis sarcophagus is a little creepy, but infinitely preferable to a bacteria-ridden corpse in your house!
In the end, I didn’t get the satisfaction of actually seeing the invader flee out of the hive. In fact, I couldn’t be sure if it hadn’t already left on it’s own. At least I knew when I finally got on the entrance reducer and put the bees to bed (a month late), that the hive was mouse free. I felt a little less guilty of beekeeper malpractice, and I’m sure the bees were much happier. Nobody likes uninvited guests, especially ones who eat you out of house and home!