Unknown Calls From Nodes to Pods

I’m running an EKS 1.17 cluster with HPA and VPA and am seeing that all of the nodes are making calls to all pods between 1 and 4 times per minute.
The calls look like below. - - [12/Oct/2020:17:21:45 +0000] "-" 408 -

This is not the AWS ELB health check and also not the readinessProbe.
Any ideas?

Cluster information:

Kubernetes version: 1.17 EKS
Cloud being used: AWS
Installation method: Terraform
Host OS: Linux