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Q: We see muskrats regularly in the Blue Heron Trail pond at Onondaga Cave State Park. I was surprised to see this one constantly raise its tail as it swam. Can you tell me more about how muskrats move through water?

A muskrat swimming on the surface holds its front feet against the chin while the hind feet alternately stroke the water in a vertical plane. On each return stroke, the hind feet are folded to reduce resistance to the water. Although the tail is trailed in a wavy or straight line and not used in surface swimming, it may act as a rudder in turning. They can swim backward as well as forward. They also use their tail vigorously when swimming underwater. Because of air trapped in their fur, they are buoyant. For more information about Missouri’s common muskrats, visit short.mdc.mo.gov/4CM. 

Q: This ant hill was 3 feet tall, and there were several other ones. What ant species made these mounds?

The Allegheny mound ant (Formica exsectoides) is the only Missouri ant species that builds such a large and neat earthen dome, , said entomologist James Trager, who is a retired restoration biologist with the Shaw Nature Reserve and currently working with The Ants of Missouri Project.

“Few ant species — especially on a global scale — can be identified solely from a photo of the nest without images of the ants themselves,” Trager said. 

Normally to accurately identify an ant species, the observer must bravely ease into the nest’s vicinity to obtain photos of the inhabitants. For Allegheny mound ants, caution is advised — they can be aggressive when a nest is disturbed.

Trager noted these ants are considered temporary social parasites. According to Antwiki, newly mated queens can start new colonies by infiltrating the nest of two related species (F. subsericea and F. fusca). Once inside the host nest, the Allegheny queen will kill the host queen. Initially, the brood will be raised by the host workers. The host ants die off over time, leaving only the Allegheny mound ants, which by then have completely taken over the colony and nest maintenance tasks.

As more Allegheny queens are added, one mound can become several by “budding,” which explains the other nests that were seen. This ant is essentially a prairie, open savanna, or woodland-prairie edge species. 

Established colonies can grow to be very large and consist of an extensive collection of interconnected, large nest-mounds with many queens. Colonies may persist for many decades and encompass a large territory.

To learn more about these ants, visit short.mdc.mo.gov/4CA.

Q: Could you help me identify this frog? 

This is a gray treefrog. In Missouri, these frogs are normally active from late March through October. They breed from early April to early July, but sometimes into August. When the nighttime air temperature warms to 60 degrees, males gather and call at breeding sites. Preferred sites include temporary wetlands, flooded field edges and ditches, and fishless permanent ponds such as sloughs, woodland ponds, and swamps. Calling males may sit at the water’s edge or station themselves on a plant, log, or branch above the water. 

Females produce 900–3,000 or more eggs, which hatch in four or five days. The tadpoles turn into froglets in about 1½–2 months. Newly transformed gray treefrog froglets are usually bright green. During the breeding season, females usually appear heavier bodied, while males have dark throats.

That white patch beneath the eye is an identifying characteristic of this species. 

Gray treefrogs overwinter below ground. Like some other frogs, they produce a substance in their blood that functions as antifreeze. People often notice them overwintering in outdoor potted plants. 

For more information, visit short.mdc.mo.gov/4CP.