It implies a casual disregard for something that may be bothersome but isn't considered serious enough to warrant action or concern.
Here's a breakdown of its meaning:
* Bedbugs: Historically, bedbugs were a common and annoying pest, causing bites and discomfort.
* Let: This implies a choice to do nothing about the problem.
* Bite: The action of the bedbugs, representing the annoyance or problem.
Example:
* "I'm not going to worry about it. If they want to cancel the party, let the bedbugs bite."
Essentially, the idiom suggests that sometimes it's better to just relax and accept things as they are, rather than stressing over minor annoyances.