IshGen 119:7 :ܕܒܐ ܒܣܬܘܐ ܡ݂ܢ ܡܬܩܐ ܕܟܪܬܗ݀ ܚܐܝܐ‏ : the bear survives during the winter by sucking its thumb
See the entire entry for mtq v.n. sucking