They might not be interpreting your specific actions, but at the lower levels they probably have a set way of playing many hands.

For instance, I sometimes find a shortstack in an SNG making a standard raise of 4xbb that leaves them with 2/3 of their stack. I call with a reasonable holding and if I hit something I will check to them. Now that the pot is the size of their stack, they go all in and I call. If I have nothing, I am more likely to go all in myself to make them fold.