By Patrick Bonin
As a kid growing up in south Louisiana, getting the chance to play with “crawfish castles” is almost a rite of passage. I can remember the time and energy my brother and I expended in attempting to unearth the hidden mudbugs, usually without any success whatsoever.
The “castles” aboveground are formed as the crawfish tunnels straight down about 40 inches or so to stay safe and reproduce during the heat of summer.
According to the Louisiana Crawfish Production Manual from the LSU Ag Center, most burrows are built at night by a single individual, and the burrow diameter is determined by the size of the mudbug building it. Typical burrows may take a few nights to complete.
The tunnel goes straight down into a chamber slightly larger than the diameter of the tunnel. In addition to keeping the crawfish safe, burrows also provide the moist, humid environment necessary for survival during Louisiana’s hot, dry summers.
And while the workmanship of the burrows was lost on us as kids, it’s pretty impressive. The walls and chamber are extensively worked by the crawfish to ensure good seals. In fact, the entrance to the burrow is eventually closed with a mud plug, and over the course of the summer, the burrow can become completely undetectable.
Burrows typically contain a single female, with survival dependent upon the length of the summer dry period, soil type and moisture available to the animal. Once sealed in, the crawfish are confined to the burrow until the hard mud plug is sufficiently softened by rainfall (or pond flooding,) allowing the mudbug to escape.
It’s vital that the female and her young leave the burrow within a reasonable time because little food is available there, so crawfish ponds are typically flooded in autumn to coincide with the main period of reproduction. As females emerge with their young (or sometimes with eggs) attached to their tails, the hatchlings are quickly separated from their mother as she moves about in open water, according to the manual.
The burrow is left behind, but it has done its job: the crawfish survived the summer, successfully reproduced and replenished the population which will serve as the basis for that coming spring’s mudbug crop.