Crawfish
Crawfish (Crayfish, Crawdads) have a long segmented tail with 4 or 5 pairs of walking legs, antenae and two large pincers, and look like mini lobsters. They can range in colour from green, yellow, pink and sometimes red.
Photo Purdue U-Peggy Sellers(left), photo marsbunny (right)
Description and Habitat
Crayfish are approx 7 cm (around 3 inches) long and appear mostly in fresh water, although they have been known in the sea. They appear in southern states and other european countries as well as some parts of canada. There are manys species of this crustacean….too many to list but they all look similar no matter where you live. They are either food, bait or pests. Generally they inhabit streams but they can occur on your turf, and sometimes this can be a major problem. This is because they love water and the water table is high enough to supply their needs.
photo Tim Gibb extension entemologist Perdue University
photos by Art Deitrich, Allen, TX
Damage
Although they do not feed on plants very much they can damage your lawn by creating small tunnels and create great mounds of dirt on your sod. When the sod dries out the hills can become like cement and very hard to get rid of. This can damage your lawn mower and make your lawn an eyesore. These photos above were taken on April 20, 2004 by Art Dietrich of Allen, Texas. He hasn’t seen the worst yet as these guys are gonna be dropping more bombshells until end of May.
Diet
They appear in the evenings for food, burrowing up out of the ground. Young craws can appear in the day on cloudy days and this can make them easy to hand pick and dispose of. They feed on small animals dead or alive. Included in thier diet are insects, snails, slugs, algae, larvae, small fish and occasionally flora and fauna. Young craws may be found during the day if it is overcast. After a major rain, these little guys can plug up your drainage systems.
Llifecycle
In early spring female crawfish burrow after mating and lay 200-400 eggs. Males then deposit sperm as fish would. The female then coats the eggs so that they may stick to her tail. Eggs hatch within 2-3 weeks. The babies are carried for up to 10 days after hatching, and this is called the ‘berry’ stage. As they grow into adults they shed their shells often and can live up to 2 years. No problem here as this is a valuable organic ingredient to the soil.
Control
Natural predators of the Crayfish include alligators, burbots, turtles, squirrels, storks, grackles and other predatory birds. I do not recommend controls since crawfish are beneficial, however if you have a major problem you can try one of these
1)Hand pick in the day or early evening
2)Crawfish traps baited with fish, chicken or other meat
3)Corn Gluten Meal (can be purchased at organic nurseries)
3)Tile and drain the areas where they appear
4)Poke a sharp stick in the hole and hope you squash them
5)High nitrogen organic fertilizer (blood and bone meal are both high in nitrogen)
6)Eat them 
April 28th, 2008 at 12:37 am
Hey guys..
I live in Madison, WI area, and I really want to keep a crayfish as a pet. Anyone know where I can buy a nice looking crayfish with reasonable price? Or where can I catch them around here?
April 5th, 2008 at 1:56 pm
Hi I own 4 Crawfish 2 boys and 2 girls I feed them crab or fish food every 2 days and they love it. I also clean my tank twice a month. I have notice that they are very aggressive at times and they do love their own space.Not only that but I like to watch them because they are in there own little world. Good luck to all my crawfish buddies…Cammy
August 8th, 2007 at 4:11 pm
Why do crawfish crawl backwards?
November 14th, 2006 at 3:26 pm
I recently became the parent of a crawfish from my daughter’s classroom and it has these fuzzy looking things on it’s back and keeps rubbing it’s legs and head. There are also tiny little creatures that look like the letter “y” all over the aquarium glass. They crawl backwards. Are these babies?
If they are, how do I go about keeping them alive? I change the water about every 2 weeks.
October 21st, 2006 at 10:40 pm
Do you know where I can find live crawfish for consumption in the Fox Cities area or of a restaraunt that prepares them (boiled cajun-style)?
I have lived in the area for over a year and have not found anything other than ordering in bulk online.
July 31st, 2006 at 10:39 am
My parents have a pond in Wisconsin. We noticed a big mound of mud on the edge of the pond w/ a hole in the center and each night it got bigger or taller and now the hole is closed. Could this be crawfish? Do crawfish live in WI. (Near the Appleton area).
June 19th, 2006 at 2:26 pm
my crayfish is pregnet she has a lot of eggs under her tail. About two weeks later their is only a few under her tail? What is going on?
September 7th, 2005 at 8:23 pm
No they do not. Their lifespan is only two years if they live that long, so they mate with several partners and a female can have as many as 12-800 eggs in her ‘berry’ stage. Regards Cahri
September 7th, 2005 at 7:37 pm
Help!
I am trying to find out if crawfish mate for life. Your help is greatly appreciated.
August 4th, 2005 at 8:27 am
What colour is it? If it is green, it may be a katydid. You can see this guy under beneficial bugs