Cockroaches lose their 'sweet tooth' to evade traps
A strain of cockroaches in Europe has evolved to outsmart the sugar traps used to eradicate them. American scientists found that the mutant cockroaches had a "reorganised" sense of taste, making them perceive the glucose used to coat poisoned bait not as sweet but rather as bitter.
A North Carolina State University team tested the theory by giving cockroaches a choice of jam or peanut butter.
They then analysed the insects' taste receptors, similar to our taste buds.
Researchers from the same team first noticed 20 years ago that some pest controllers were failing to eradicate cockroaches from properties, because the insects were simply refusing to eat the bait.
Dr Coby Schal explained in the journal Science that this new study had revealed the "neural mechanism" behind this refusal.Read More