An expert warns about a key sign of bed bugs.

Bed bugs are small insects that drink human blood. They live near beds to be close to food. Cleanliness does not stop them. They give off a smell like almonds when many are together.

This smell happens when bed bugs send out pheromones. People often miss it and think it's dampness.

The smell is sweet and like almonds. Many people don't know it's from bed bugs and think it's something else. Bed bugs are good at hiding.

Bed bugs are hard to see because they hide in small spaces. Their flat bodies help them fit into tiny cracks.

Bed bugs only come out to eat when people are asleep. They eat for a few minutes and then hide again. This usually happens between 2am and 5am.

Rust-colored marks on beds can be a sign of bed bugs. People often think these marks are just dirt.

Dark brown spots on beds can mean bed bugs are there.

Blood on beds can also be a sign of bed bugs. This blood is usually from a bed bug being squashed.

Bed bug bites can happen in a line or in a small area. This can help confirm bed bugs are present.

Bed bug bites can look like they happen in a pattern, like 'breakfast, lunch, and dinner'.

Bed bugs reproduce very quickly. A female can lay many eggs in just a few days. This means a small problem can become big quickly.

To check for bed bugs, take off all bed sheets and look at the seams and mattress. Check the bed frame too, especially in corners.

If you find bed bugs, wash all bedding and clothes in hot water. Then, dry them on high heat for at least 30 minutes.

The British Association of Dermatologists says using heat is a good way to kill bed bugs and their eggs.