BobK
29th June 2006, 11:34 PM
New Scientist (http://www.newscientist.com/article.ns?id=dn9436)
Desert ants have an internal system - like a pedometer - that keeps track of how many steps they take, according to a new study. The insects seem to rely on this system to find their way back to the nest after foraging. Other insects may also possess this pedometer-like system.
They decided to measure how much the modified ants over- or underestimated distances. First, they allowed unaltered ants to learn the distance between a nesting site and food source separated by a 10-metre aluminium channel.
After a set time the ants were removed from the food source and immobilised temporarily in a wax-like material. Wolf’s team then either removed about 1 millimetre from the tips of the insects’ legs or attached 1-millimetre “stilts” made of lightweight bristles.
The ants were then placed back at the feeding site and allowed to return to their nest along another aluminium channel – which did not connect to the nest.
The researchers found that ants walking on stilts typically travelled 50% further than the normal distance and then began pacing back and forth looking for home.
And those with shortened legs paced back and forth in the channel after travelling, on average, only 50% of the normal distance to the nest.
Sounds interesting. Wonder if the experiment is valid tho'.
A look at the enlargement of the image seems to indicate the adjustments to leg length are not proportional to distance traveled.
Desert ants have an internal system - like a pedometer - that keeps track of how many steps they take, according to a new study. The insects seem to rely on this system to find their way back to the nest after foraging. Other insects may also possess this pedometer-like system.
They decided to measure how much the modified ants over- or underestimated distances. First, they allowed unaltered ants to learn the distance between a nesting site and food source separated by a 10-metre aluminium channel.
After a set time the ants were removed from the food source and immobilised temporarily in a wax-like material. Wolf’s team then either removed about 1 millimetre from the tips of the insects’ legs or attached 1-millimetre “stilts” made of lightweight bristles.
The ants were then placed back at the feeding site and allowed to return to their nest along another aluminium channel – which did not connect to the nest.
The researchers found that ants walking on stilts typically travelled 50% further than the normal distance and then began pacing back and forth looking for home.
And those with shortened legs paced back and forth in the channel after travelling, on average, only 50% of the normal distance to the nest.
Sounds interesting. Wonder if the experiment is valid tho'.
A look at the enlargement of the image seems to indicate the adjustments to leg length are not proportional to distance traveled.