How do fish sleep? Do they float in place or rest on the bottom?
Fish don't really sleep the way that mammals do, says DNR aquatic education specialist Roland Sigurdson. They do go into a resting state to conserve energy. Many minnows, for example, are very active in schools during the day, but scatter and remain motionless at night. Largemouth bass and perch rest on or under logs at night. Catfish swim up under a brush pile or riverbank for shelter during the day and are more active at night.
Our church is having a Sunday school rally and is releasing balloons with strings on them into the air. I don't think it is a very good idea.
Your concern is legitimate. Animals can become entangled in balloon strings, or they can choke or starve if they try to eat a balloon. Scientists have found dead ducks in Minnesota with shreds of latex balloons in their digestive tracts. Even if wildlife don't eat them, the balloons create litter wherever they end up.
We encourage you to help your church to find a more earth friendly activity. Perhaps teachers could distribute tree seedlings. Or each child could pot a plant and watch it grow as they grow.
Last fall I noticed gray squirrels taking landscape rocks from around my shrubs and carrying them off. Sometimes they left them in the grass, and I even found some of these rocks up in the branch crotches of trees. Why do they do this?
DNR wildlife educator Jan Welsh says rock-caching is probably misplaced nut-caching behavior. Squirrels are "hard-wired" to collect and bury nuts as a food source for later on in the winter. The squirrels seem to be getting the behavior right with the wrong objects. It should be interesting when they try to retrieve and eat their stash.
My cousin found a lamprey floating dead in the water on lower Big Pine Lake in Pine County. How could it get into our lake? Do these things attach to humans? Is this something to be concerned about?
The lamprey you saw was likely a silver or chestnut lamprey, says DNR aquatic education specialist Roland Sigurdson. They are two of Minnesota's five native lamprey species. Unlike the sea lamprey, which is an invasive nonnative species found in Lake Superior and its tributaries, native lampreys are a normal part of the lake ecosystem and pose no threat to either humans or other fish populations. For more information on Minnesota lamprey, call the DNR Information Center, listed on page 3, and request the brochure "Native Minnesota Lamprey -- The Misunderstood Fish."
For several years a single swan has spent a few days on our little lake in Pine County. Last year the swan seemed to have taken to a goose and stayed longer. Could they have mated?
Swans are not the most discerning birds, and occasionally they do fix their attention on non-swans. DNR wildlife educator Jan Welsh assures us that even if the swan and goose hang out together they won't mate, so you won't be seeing any little "gwans" or "sweese" on your lake.
Will bluebirds nest again if they lose their eggs? My bluebird house went down in a windstorm. When I put it back up the birds were still in the area, but I haven't seen them back since.
Most birds will re-nest if it's not too late in the season, says DNR wildlife educator Jan Welsh. Perhaps your birds simply found a less breezy spot for their second try.
In what specific habitat do ground hornets build their nests, and how do I avoid them?
University of Minnesota entomology professor Jeff Hahn says ground hornets (also known as yellow jackets) live in a variety of habitats, so you can't really avoid them by avoiding one kind of setting or another. The good news is, the nests are few and far between, so your odds of encountering one are rather slim. If you do see a nest, Hahn recommends you walk slowly around it, and the hornets should leave you alone. He also notes nests are built new each year. That means that if you know where the nests are this year, you won't necessarily know where they are next year.