The insects release an anticoagulant to get blood flowing, and they also excrete a numbing agent so their bites don't often stir a victim's slumber.

这些昆虫会释放出一种抗凝血剂去维持血液的流动，同时也会分泌一种使人失去知觉的物质，所以他们的叮咬并不会影响受害者的睡眠。

The sound of bagpipes doesn't stir my blood.

风笛声激不起我的热情。